| 1 | two-sum | Python Rust | :memo: | Easy |
| 2 | add-two-numbers | Python | :memo: | Medium |
| 3 | longest-substring-without-repeating-characters | Python | :memo: | Medium |
| 4 | median-of-two-sorted-arrays | Python | :memo: | Hard |
| 5 | longest-palindromic-substring | Python | :memo: | Medium |
| 6 | zigzag-conversion | Python | :memo: | Medium |
| 7 | reverse-integer | Python | :memo: | Easy |
| 8 | string-to-integer-atoi | Python | | Medium |
| 9 | palindrome-number | Python | :memo: | Easy |
| 10 | regular-expression-matching | Python | :memo: | Hard |
| 11 | container-with-most-water | Python | :memo: | Medium |
| 12 | integer-to-roman | Python | | Medium |
| 13 | roman-to-integer | Python | | Easy |
| 14 | longest-common-prefix | Python | :memo: | Easy |
| 15 | 3sum | Python | | Medium |
| 16 | 3sum-closest | Python | | Medium |
| 17 | letter-combinations-of-a-phone-number | Python | :memo: | Medium |
| 18 | 4sum | Python | | Medium |
| 19 | remove-nth-node-from-end-of-list | Python | :memo: | Medium |
| 20 | valid-parentheses | Python | :memo: | Easy |
| 21 | merge-two-sorted-lists | Python | :memo: | Easy |
| 22 | generate-parentheses | Python | :memo: | Medium |
| 23 | merge-k-sorted-lists | Python | :memo: | Hard |
| 24 | swap-nodes-in-pairs | Python | | Medium |
| 25 | reverse-nodes-in-k-group | Python | | Hard |
| 26 | remove-duplicates-from-sorted-array | Python | :memo: | Easy |
| 27 | remove-element | Python | :memo: | Easy |
| 28 | implement-strstr | Python | | Easy |
| 29 | divide-two-integers | | | Medium |
| 30 | substring-with-concatenation-of-all-words | | | Hard |
| 31 | next-permutation | | :memo: | Medium |
| 32 | longest-valid-parentheses | | :memo: | Hard |
| 33 | search-in-rotated-sorted-array | | :memo: | Medium |
| 34 | find-first-and-last-position-of-element-in-sorted-array | Python | :memo: | Medium |
| 35 | search-insert-position | Python | | Easy |
| 36 | valid-sudoku | | :memo: | Medium |
| 37 | sudoku-solver | | :memo: | Hard |
| 38 | count-and-say | Python | | Easy |
| 39 | combination-sum | Python | | Medium |
| 40 | combination-sum-ii | | | Medium |
| 41 | first-missing-positive | Python | :memo: | Hard |
| 42 | trapping-rain-water | | :memo: | Hard |
| 43 | multiply-strings | | | Medium |
| 44 | wildcard-matching | | :memo: | Hard |
| 45 | jump-game-ii | | | Hard |
| 46 | permutations | | :memo: | Medium |
| 47 | permutations-ii | | | Medium |
| 48 | rotate-image | Python | :memo: | Medium |
| 49 | group-anagrams | | :memo: | Medium |
| 50 | powx-n | Python | :memo: | Medium |
| 51 | n-queens | | :memo: | Hard |
| 52 | n-queens-ii | | :memo: | Hard |
| 53 | maximum-subarray | Python | :memo: | Easy |
| 54 | spiral-matrix | Python | :memo: | Medium |
| 55 | jump-game | Python | :memo: | Medium |
| 56 | merge-intervals | Python | :memo: | Medium |
| 57 | insert-interval | Python | :memo: | Hard |
| 58 | length-of-last-word | Python | | Easy |
| 59 | spiral-matrix-ii | | | Medium |
| 60 | permutation-sequence | | | Medium |
| 61 | rotate-list | | :memo: | Medium |
| 62 | unique-paths | | | Medium |
| 63 | unique-paths-ii | | :memo: | Medium |
| 64 | minimum-path-sum | | :memo: | Medium |
| 65 | valid-number | | | Hard |
| 66 | plus-one | Python | | Easy |
| 67 | add-binary | Python | | Easy |
| 68 | text-justification | | | Hard |
| 69 | sqrtx | | :memo: | Easy |
| 70 | climbing-stairs | Python | :memo: | Easy |
| 71 | simplify-path | Python | | Medium |
| 72 | edit-distance | | :memo: | Hard |
| 73 | set-matrix-zeroes | Python | :memo: | Medium |
| 74 | search-a-2d-matrix | | :memo: | Medium |
| 75 | sort-colors | Python | :memo: | Medium |
| 76 | minimum-window-substring | | :memo: | Hard |
| 77 | combinations | Python | :memo: | Medium |
| 78 | subsets | Python | | Medium |
| 79 | word-search | Python | | Medium |
| 80 | remove-duplicates-from-sorted-array-ii | Python | | Medium |
| 81 | search-in-rotated-sorted-array-ii | | | Medium |
| 82 | remove-duplicates-from-sorted-list-ii | | | Medium |
| 83 | remove-duplicates-from-sorted-list | Python | :memo: | Easy |
| 84 | largest-rectangle-in-histogram | | :memo: | Hard |
| 85 | maximal-rectangle | | :memo: | Hard |
| 86 | partition-list | Python | :memo: | Medium |
| 87 | scramble-string | | | Hard |
| 88 | merge-sorted-array | Python | :memo: | Easy |
| 89 | gray-code | | | Medium |
| 90 | subsets-ii | | | Medium |
| 91 | decode-ways | | | Medium |
| 92 | reverse-linked-list-ii | | :memo: | Medium |
| 93 | restore-ip-addresses | Python | :memo: | Medium |
| 94 | binary-tree-inorder-traversal | Python | :memo: | Medium |
| 95 | unique-binary-search-trees-ii | | :memo: | Medium |
| 96 | unique-binary-search-trees | | :memo: | Medium |
| 97 | interleaving-string | Python | :memo: | Hard |
| 98 | validate-binary-search-tree | | :memo: | Medium |
| 99 | recover-binary-search-tree | | :memo: | Hard |
| 100 | same-tree | Python | :memo: | Easy |
| 101 | symmetric-tree | Python | :memo: | Easy |
| 102 | binary-tree-level-order-traversal | | :memo: | Medium |
| 103 | binary-tree-zigzag-level-order-traversal | | | Medium |
| 104 | maximum-depth-of-binary-tree | Python | :memo: | Easy |
| 105 | construct-binary-tree-from-preorder-and-inorder-traversal | | :memo: | Medium |
| 106 | construct-binary-tree-from-inorder-and-postorder-traversal | | :memo: | Medium |
| 107 | binary-tree-level-order-traversal-ii | Python | | Easy |
| 108 | convert-sorted-array-to-binary-search-tree | Python | | Easy |
| 109 | convert-sorted-list-to-binary-search-tree | | :memo: | Medium |
| 110 | balanced-binary-tree | | | Easy |
| 111 | minimum-depth-of-binary-tree | Python | :memo: | Easy |
| 112 | path-sum | Python | :memo: | Easy |
| 113 | path-sum-ii | Python | | Medium |
| 114 | flatten-binary-tree-to-linked-list | | | Medium |
| 115 | distinct-subsequences | | | Hard |
| 116 | populating-next-right-pointers-in-each-node | | | Medium |
| 117 | populating-next-right-pointers-in-each-node-ii | | | Medium |
| 118 | pascals-triangle | Python | :memo: | Easy |
| 119 | pascals-triangle-ii | Python | | Easy |
| 120 | triangle | | | Medium |
| 121 | best-time-to-buy-and-sell-stock | Python | :memo: | Easy |
| 122 | best-time-to-buy-and-sell-stock-ii | Python | :memo: | Easy |
| 123 | best-time-to-buy-and-sell-stock-iii | | | Hard |
| 124 | binary-tree-maximum-path-sum | | :memo: | Hard |
| 125 | valid-palindrome | Python | | Easy |
| 126 | word-ladder-ii | | | Hard |
| 127 | word-ladder | | :memo: | Medium |
| 128 | longest-consecutive-sequence | | :memo: | Hard |
| 129 | sum-root-to-leaf-numbers | | | Medium |
| 130 | surrounded-regions | | | Medium |
| 131 | palindrome-partitioning | | | Medium |
| 132 | palindrome-partitioning-ii | | | Hard |
| 133 | clone-graph | | | Medium |
| 134 | gas-station | Python | :memo: | Medium |
| 135 | candy | | :memo: | Hard |
| 136 | single-number | Python | :memo: | Easy |
| 137 | single-number-ii | Python | :memo: | Medium |
| 138 | copy-list-with-random-pointer | | :memo: | Medium |
| 139 | word-break | | :memo: | Medium |
| 140 | word-break-ii | | :memo: | Hard |
| 141 | linked-list-cycle | Python | :memo: | Easy |
| 142 | linked-list-cycle-ii | | :memo: | Medium |
| 143 | reorder-list | | | Medium |
| 144 | binary-tree-preorder-traversal | | :memo: | Medium |
| 145 | binary-tree-postorder-traversal | | :memo: | Hard |
| 146 | lru-cache | | :memo: | Medium |
| 147 | insertion-sort-list | | | Medium |
| 148 | sort-list | | | Medium |
| 149 | max-points-on-a-line | | :memo: | Hard |
| 150 | evaluate-reverse-polish-notation | | | Medium |
| 151 | reverse-words-in-a-string | | | Medium |
| 152 | maximum-product-subarray | | | Medium |
| 153 | find-minimum-in-rotated-sorted-array | | :memo: | Medium |
| 154 | find-minimum-in-rotated-sorted-array-ii | | | Hard |
| 155 | min-stack | | | Easy |
| 156 | binary-tree-upside-down | :lock: | | Medium |
| 157 | read-n-characters-given-read4 | :lock: | | Easy |
| 158 | read-n-characters-given-read4-ii-call-multiple-times | :lock: | | Hard |
| 159 | longest-substring-with-at-most-two-distinct-characters | :lock: | :memo: | Hard |
| 160 | intersection-of-two-linked-lists | | :memo: | Easy |
| 161 | one-edit-distance | :lock: | :memo: | Medium |
| 162 | find-peak-element | | :memo: | Medium |
| 163 | missing-ranges | :lock: | | Medium |
| 164 | maximum-gap | | :memo: | Hard |
| 165 | compare-version-numbers | | | Medium |
| 166 | fraction-to-recurring-decimal | | :memo: | Medium |
| 167 | two-sum-ii-input-array-is-sorted | | :memo: | Easy |
| 168 | excel-sheet-column-title | | | Easy |
| 169 | majority-element | | :memo: | Easy |
| 170 | two-sum-iii-data-structure-design | :lock: | | Easy |
| 171 | excel-sheet-column-number | | | Easy |
| 172 | factorial-trailing-zeroes | | | Easy |
| 173 | binary-search-tree-iterator | | :memo: | Medium |
| 174 | dungeon-game | | | Hard |
| 179 | largest-number | | :memo: | Medium |
| 186 | reverse-words-in-a-string-ii | :lock: | | Medium |
| 187 | repeated-dna-sequences | | | Medium |
| 188 | best-time-to-buy-and-sell-stock-iv | | | Hard |
| 189 | rotate-array | Python | :memo: | Easy |
| 190 | reverse-bits | | | Easy |
| 191 | number-of-1-bits | | :memo: | Easy |
| 198 | house-robber | | :memo: | Easy |
| 199 | binary-tree-right-side-view | | :memo: | Medium |
| 200 | number-of-islands | | :memo: | Medium |
| 201 | bitwise-and-of-numbers-range | | | Medium |
| 202 | happy-number | | | Easy |
| 203 | remove-linked-list-elements | | | Easy |
| 204 | count-primes | | | Easy |
| 205 | isomorphic-strings | | | Easy |
| 206 | reverse-linked-list | Python | :memo: | Easy |
| 207 | course-schedule | | | Medium |
| 208 | implement-trie-prefix-tree | | :memo: | Medium |
| 209 | minimum-size-subarray-sum | | :memo: | Medium |
| 210 | course-schedule-ii | | :memo: | Medium |
| 211 | add-and-search-word-data-structure-design | | | Medium |
| 212 | word-search-ii | | | Hard |
| 213 | house-robber-ii | | | Medium |
| 214 | shortest-palindrome | | :memo: | Hard |
| 215 | kth-largest-element-in-an-array | | :memo: | Medium |
| 216 | combination-sum-iii | | | Medium |
| 217 | contains-duplicate | | :memo: | Easy |
| 218 | the-skyline-problem | | :memo: | Hard |
| 219 | contains-duplicate-ii | | :memo: | Easy |
| 220 | contains-duplicate-iii | | :memo: | Medium |
| 221 | maximal-square | | :memo: | Medium |
| 222 | count-complete-tree-nodes | | :memo: | Medium |
| 223 | rectangle-area | | | Medium |
| 224 | basic-calculator | | :memo: | Hard |
| 225 | implement-stack-using-queues | | :memo: | Easy |
| 226 | invert-binary-tree | | :memo: | Easy |
| 227 | basic-calculator-ii | Python | | Medium |
| 228 | summary-ranges | | :memo: | Medium |
| 229 | majority-element-ii | | | Medium |
| 230 | kth-smallest-element-in-a-bst | | :memo: | Medium |
| 231 | power-of-two | | :memo: | Easy |
| 232 | implement-queue-using-stacks | | :memo: | Easy |
| 233 | number-of-digit-one | | :memo: | Hard |
| 234 | palindrome-linked-list | | | Easy |
| 235 | lowest-common-ancestor-of-a-binary-search-tree | | :memo: | Easy |
| 236 | lowest-common-ancestor-of-a-binary-tree | | :memo: | Medium |
| 237 | delete-node-in-a-linked-list | Python | :memo: | Easy |
| 238 | product-of-array-except-self | | :memo: | Medium |
| 239 | sliding-window-maximum | | :memo: | Hard |
| 240 | search-a-2d-matrix-ii | Python | :memo: | Medium |
| 241 | different-ways-to-add-parentheses | | | Medium |
| 242 | valid-anagram | Python | :memo: | Easy |
| 243 | shortest-word-distance | :lock: | :memo: | Easy |
| 244 | shortest-word-distance-ii | :lock: | :memo: | Medium |
| 245 | shortest-word-distance-iii | :lock: | | Medium |
| 246 | strobogrammatic-number | :lock: | | Easy |
| 247 | strobogrammatic-number-ii | :lock: | | Medium |
| 248 | strobogrammatic-number-iii | :lock: | | Hard |
| 249 | group-shifted-strings | :lock: | | Medium |
| 250 | count-univalue-subtrees | :lock: | :memo: | Medium |
| 251 | flatten-2d-vector | :lock: | | Medium |
| 252 | meeting-rooms | :lock: | :memo: | Easy |
| 253 | meeting-rooms-ii | :lock: | :memo: | Medium |
| 254 | factor-combinations | :lock: | | Medium |
| 255 | verify-preorder-sequence-in-binary-search-tree | :lock: | | Medium |
| 256 | paint-house | :lock: | | Easy |
| 257 | binary-tree-paths | | :memo: | Easy |
| 258 | add-digits | | | Easy |
| 259 | 3sum-smaller | :lock: | :memo: | Medium |
| 260 | single-number-iii | | | Medium |
| 261 | graph-valid-tree | :lock: | | Medium |
| 263 | ugly-number | Python | | Easy |
| 264 | ugly-number-ii | Python | :memo: | Medium |
| 265 | paint-house-ii | :lock: | | Hard |
| 266 | palindrome-permutation | :lock: | :memo: | Easy |
| 267 | palindrome-permutation-ii | :lock: | :memo: | Medium |
| 268 | missing-number | | :memo: | Easy |
| 269 | alien-dictionary | :lock: | | Hard |
| 270 | closest-binary-search-tree-value | :lock: | :memo: | Easy |
| 271 | encode-and-decode-strings | :lock: | :memo: | Medium |
| 272 | closest-binary-search-tree-value-ii | :lock: | | Hard |
| 273 | integer-to-english-words | | :memo: | Hard |
| 274 | h-index | Python | :memo: | Medium |
| 275 | h-index-ii | Python | :memo: | Medium |
| 276 | paint-fence | :lock: | | Easy |
| 277 | find-the-celebrity | :lock: | | Medium |
| 278 | first-bad-version | | :memo: | Easy |
| 279 | perfect-squares | | | Medium |
| 280 | wiggle-sort | :lock: | :memo: | Medium |
| 281 | zigzag-iterator | :lock: | | Medium |
| 282 | expression-add-operators | | :memo: | Hard |
| 283 | move-zeroes | | :memo: | Easy |
| 284 | peeking-iterator | | | Medium |
| 285 | inorder-successor-in-bst | :lock: | :memo: | Medium |
| 286 | walls-and-gates | :lock: | :memo: | Medium |
| 287 | find-the-duplicate-number | | :memo: | Medium |
| 288 | unique-word-abbreviation | :lock: | :memo: | Medium |
| 289 | game-of-life | | :memo: | Medium |
| 290 | word-pattern | | | Easy |
| 291 | word-pattern-ii | :lock: | | Hard |
| 292 | nim-game | | :memo: | Easy |
| 293 | flip-game | :lock: | | Easy |
| 294 | flip-game-ii | :lock: | | Medium |
| 295 | find-median-from-data-stream | | :memo: | Hard |
| 296 | best-meeting-point | :lock: | :memo: | Hard |
| 297 | serialize-and-deserialize-binary-tree | | :memo: | Hard |
| 298 | binary-tree-longest-consecutive-sequence | :lock: | :memo: | Medium |
| 299 | bulls-and-cows | | | Easy |
| 300 | longest-increasing-subsequence | | :memo: | Medium |
| 301 | remove-invalid-parentheses | | :memo: | Hard |
| 302 | smallest-rectangle-enclosing-black-pixels | :lock: | :memo: | Hard |
| 303 | range-sum-query-immutable | | :memo: | Easy |
| 304 | range-sum-query-2d-immutable | | :memo: | Medium |
| 305 | number-of-islands-ii | :lock: | :memo: | Hard |
| 306 | additive-number | | | Medium |
| 307 | range-sum-query-mutable | | :memo: | Medium |
| 308 | range-sum-query-2d-mutable | :lock: | | Hard |
| 309 | best-time-to-buy-and-sell-stock-with-cooldown | | | Medium |
| 310 | minimum-height-trees | | | Medium |
| 311 | sparse-matrix-multiplication | :lock: | | Medium |
| 312 | burst-balloons | | :memo: | Hard |
| 313 | super-ugly-number | Python | | Medium |
| 314 | binary-tree-vertical-order-traversal | :lock: | | Medium |
| 315 | count-of-smaller-numbers-after-self | | | Hard |
| 316 | remove-duplicate-letters | | :memo: | Hard |
| 317 | shortest-distance-from-all-buildings | :lock: | | Hard |
| 318 | maximum-product-of-word-lengths | | :memo: | Medium |
| 319 | bulb-switcher | | | Medium |
| 320 | generalized-abbreviation | :lock: | :memo: | Medium |
| 321 | create-maximum-number | | | Hard |
| 322 | coin-change | | :memo: | Medium |
| 323 | number-of-connected-components-in-an-undirected-graph | :lock: | | Medium |
| 324 | wiggle-sort-ii | Python | | Medium |
| 325 | maximum-size-subarray-sum-equals-k | :lock: | | Medium |
| 326 | power-of-three | | :memo: | Easy |
| 327 | count-of-range-sum | | | Hard |
| 328 | odd-even-linked-list | | :memo: | Medium |
| 329 | longest-increasing-path-in-a-matrix | | :memo: | Hard |
| 330 | patching-array | | :memo: | Hard |
| 331 | verify-preorder-serialization-of-a-binary-tree | | :memo: | Medium |
| 332 | reconstruct-itinerary | | | Medium |
| 333 | largest-bst-subtree | :lock: | | Medium |
| 334 | increasing-triplet-subsequence | | | Medium |
| 335 | self-crossing | Python | | Hard |
| 336 | palindrome-pairs | | | Hard |
| 337 | house-robber-iii | | | Medium |
| 338 | counting-bits | | :memo: | Medium |
| 339 | nested-list-weight-sum | :lock: | :memo: | Easy |
| 340 | longest-substring-with-at-most-k-distinct-characters | :lock: | :memo: | Hard |
| 341 | flatten-nested-list-iterator | | | Medium |
| 342 | power-of-four | | | Easy |
| 343 | integer-break | | | Medium |
| 344 | reverse-string | | | Easy |
| 345 | reverse-vowels-of-a-string | | | Easy |
| 346 | moving-average-from-data-stream | :lock: | | Easy |
| 347 | top-k-frequent-elements | Python | :memo: | Medium |
| 348 | design-tic-tac-toe | :lock: | | Medium |
| 349 | intersection-of-two-arrays | | :memo: | Easy |
| 350 | intersection-of-two-arrays-ii | | | Easy |
| 351 | android-unlock-patterns | :lock: | :memo: | Medium |
| 352 | data-stream-as-disjoint-intervals | | | Hard |
| 353 | design-snake-game | :lock: | | Medium |
| 354 | russian-doll-envelopes | | | Hard |
| 355 | design-twitter | | | Medium |
| 356 | line-reflection | :lock: | | Medium |
| 357 | count-numbers-with-unique-digits | | | Medium |
| 358 | rearrange-string-k-distance-apart | :lock: | | Hard |
| 359 | logger-rate-limiter | :lock: | | Easy |
| 360 | sort-transformed-array | :lock: | | Medium |
| 361 | bomb-enemy | :lock: | | Medium |
| 362 | design-hit-counter | :lock: | | Medium |
| 363 | max-sum-of-rectangle-no-larger-than-k | | | Hard |
| 364 | nested-list-weight-sum-ii | :lock: | | Medium |
| 365 | water-and-jug-problem | | | Medium |
| 366 | find-leaves-of-binary-tree | :lock: | | Medium |
| 367 | valid-perfect-square | | | Easy |
| 368 | largest-divisible-subset | | | Medium |
| 369 | plus-one-linked-list | :lock: | | Medium |
| 370 | range-addition | :lock: | :memo: | Medium |
| 371 | sum-of-two-integers | | | Easy |
| 372 | super-pow | | | Medium |
| 373 | find-k-pairs-with-smallest-sums | | | Medium |
| 374 | guess-number-higher-or-lower | | :memo: | Easy |
| 375 | guess-number-higher-or-lower-ii | | :memo: | Medium |
| 376 | wiggle-subsequence | | :memo: | Medium |
| 377 | combination-sum-iv | | | Medium |
| 378 | kth-smallest-element-in-a-sorted-matrix | | | Medium |
| 379 | design-phone-directory | :lock: | | Medium |
| 380 | insert-delete-getrandom-o1 | | | Medium |
| 381 | insert-delete-getrandom-o1-duplicates-allowed | | :memo: | Hard |
| 382 | linked-list-random-node | | | Medium |
| 383 | ransom-note | | | Easy |
| 384 | shuffle-an-array | | :memo: | Medium |
| 385 | mini-parser | | | Medium |
| 386 | lexicographical-numbers | | | Medium |
| 387 | first-unique-character-in-a-string | | :memo: | Easy |
| 388 | longest-absolute-file-path | | | Medium |
| 389 | find-the-difference | | | Easy |
| 390 | elimination-game | | | Medium |
| 391 | perfect-rectangle | | | Hard |
| 392 | is-subsequence | | | Easy |
| 393 | utf-8-validation | | :memo: | Medium |
| 394 | decode-string | | | Medium |
| 395 | longest-substring-with-at-least-k-repeating-characters | | | Medium |
| 396 | rotate-function | | | Medium |
| 397 | integer-replacement | | | Medium |
| 398 | random-pick-index | | | Medium |
| 399 | evaluate-division | | | Medium |
| 400 | nth-digit | | | Medium |
| 401 | binary-watch | | | Easy |
| 402 | remove-k-digits | | | Medium |
| 403 | frog-jump | | :memo: | Hard |
| 404 | sum-of-left-leaves | | | Easy |
| 405 | convert-a-number-to-hexadecimal | Python | | Easy |
| 406 | queue-reconstruction-by-height | | :memo: | Medium |
| 407 | trapping-rain-water-ii | | | Hard |
| 408 | valid-word-abbreviation | :lock: | | Easy |
| 409 | longest-palindrome | | :memo: | Easy |
| 410 | split-array-largest-sum | | :memo: | Hard |
| 411 | minimum-unique-word-abbreviation | :lock: | | Hard |
| 412 | fizz-buzz | | :memo: | Easy |
| 413 | arithmetic-slices | | :memo: | Medium |
| 414 | third-maximum-number | | | Easy |
| 415 | add-strings | | | Easy |
| 416 | partition-equal-subset-sum | | | Medium |
| 417 | pacific-atlantic-water-flow | | | Medium |
| 418 | sentence-screen-fitting | :lock: | | Medium |
| 419 | battleships-in-a-board | | | Medium |
| 420 | strong-password-checker | Python | | Hard |
| 421 | maximum-xor-of-two-numbers-in-an-array | | | Medium |
| 422 | valid-word-square | :lock: | | Easy |
| 423 | reconstruct-original-digits-from-english | | :memo: | Medium |
| 424 | longest-repeating-character-replacement | | | Medium |
| 425 | word-squares | :lock: | | Hard |
| 432 | all-oone-data-structure | | | Hard |
| 433 | minimum-genetic-mutation | | | Medium |
| 434 | number-of-segments-in-a-string | | :memo: | Easy |
| 435 | non-overlapping-intervals | | :memo: | Medium |
| 436 | find-right-interval | | :memo: | Medium |
| 437 | path-sum-iii | | | Easy |
| 438 | find-all-anagrams-in-a-string | Python | | Medium |
| 439 | ternary-expression-parser | :lock: | | Medium |
| 440 | k-th-smallest-in-lexicographical-order | | | Hard |
| 441 | arranging-coins | | | Easy |
| 442 | find-all-duplicates-in-an-array | | | Medium |
| 443 | string-compression | | :memo: | Easy |
| 444 | sequence-reconstruction | :lock: | | Medium |
| 445 | add-two-numbers-ii | | | Medium |
| 446 | arithmetic-slices-ii-subsequence | | :memo: | Hard |
| 447 | number-of-boomerangs | | | Easy |
| 448 | find-all-numbers-disappeared-in-an-array | | | Easy |
| 449 | serialize-and-deserialize-bst | | :memo: | Medium |
| 450 | delete-node-in-a-bst | | :memo: | Medium |
| 451 | sort-characters-by-frequency | | | Medium |
| 452 | minimum-number-of-arrows-to-burst-balloons | | :memo: | Medium |
| 453 | minimum-moves-to-equal-array-elements | | :memo: | Easy |
| 454 | 4sum-ii | Python | | Medium |
| 455 | assign-cookies | Python | | Easy |
| 456 | 132-pattern | | :memo: | Medium |
| 457 | circular-array-loop | | | Medium |
| 458 | poor-pigs | Python | :memo: | Hard |
| 459 | repeated-substring-pattern | | | Easy |
| 460 | lfu-cache | | | Hard |
| 461 | hamming-distance | Python | | Easy |
| 462 | minimum-moves-to-equal-array-elements-ii | | :memo: | Medium |
| 463 | island-perimeter | | | Easy |
| 464 | can-i-win | | | Medium |
| 465 | optimal-account-balancing | :lock: | | Hard |
| 466 | count-the-repetitions | | :memo: | Hard |
| 467 | unique-substrings-in-wraparound-string | | | Medium |
| 468 | validate-ip-address | | | Medium |
| 469 | convex-polygon | :lock: | | Medium |
| 471 | encode-string-with-shortest-length | :lock: | | Hard |
| 472 | concatenated-words | | | Hard |
| 473 | matchsticks-to-square | | :memo: | Medium |
| 474 | ones-and-zeroes | | :memo: | Medium |
| 475 | heaters | | | Easy |
| 476 | number-complement | | | Easy |
| 477 | total-hamming-distance | | :memo: | Medium |
| 479 | largest-palindrome-product | | | Hard |
| 480 | sliding-window-median | | :memo: | Hard |
| 481 | magical-string | | | Medium |
| 482 | license-key-formatting | | | Easy |
| 483 | smallest-good-base | | | Hard |
| 484 | find-permutation | :lock: | :memo: | Medium |
| 485 | max-consecutive-ones | Python | | Easy |
| 486 | predict-the-winner | | :memo: | Medium |
| 487 | max-consecutive-ones-ii | :lock: | | Medium |
| 488 | zuma-game | | | Hard |
| 490 | the-maze | :lock: | :memo: | Medium |
| 491 | increasing-subsequences | | | Medium |
| 492 | construct-the-rectangle | | | Easy |
| 493 | reverse-pairs | | :memo: | Hard |
| 494 | target-sum | | :memo: | Medium |
| 495 | teemo-attacking | | :memo: | Medium |
| 496 | next-greater-element-i | | :memo: | Easy |
| 498 | diagonal-traverse | | | Medium |
| 499 | the-maze-iii | :lock: | | Hard |
| 500 | keyboard-row | | | Easy |
| 501 | find-mode-in-binary-search-tree | | | Easy |
| 502 | ipo | | :memo: | Hard |
| 503 | next-greater-element-ii | | :memo: | Medium |
| 504 | base-7 | | | Easy |
| 505 | the-maze-ii | :lock: | :memo: | Medium |
| 506 | relative-ranks | Python | | Easy |
| 507 | perfect-number | | :memo: | Easy |
| 508 | most-frequent-subtree-sum | | | Medium |
| 509 | inorder-successor-in-bst-ii | :lock: | :memo: | Medium |
| 511 | all-paths-from-source-lead-to-destination | :lock: | | Medium |
| 513 | find-bottom-left-tree-value | | | Medium |
| 514 | freedom-trail | | | Hard |
| 515 | find-largest-value-in-each-tree-row | | | Medium |
| 516 | longest-palindromic-subsequence | | | Medium |
| 517 | super-washing-machines | | :memo: | Hard |
| 518 | coin-change-2 | | | Medium |
| 520 | detect-capital | | | Easy |
| 521 | longest-uncommon-subsequence-i | | :memo: | Easy |
| 522 | longest-uncommon-subsequence-ii | | :memo: | Medium |
| 523 | continuous-subarray-sum | | :memo: | Medium |
| 524 | longest-word-in-dictionary-through-deleting | | :memo: | Medium |
| 525 | contiguous-array | | :memo: | Medium |
| 526 | beautiful-arrangement | Python | :memo: | Medium |
| 527 | word-abbreviation | :lock: | :memo: | Hard |
| 529 | minesweeper | | | Medium |
| 530 | minimum-absolute-difference-in-bst | | | Easy |
| 531 | lonely-pixel-i | :lock: | | Medium |
| 532 | k-diff-pairs-in-an-array | | | Easy |
| 533 | lonely-pixel-ii | :lock: | | Medium |
| 535 | encode-and-decode-tinyurl | | :memo: | Medium |
| 536 | construct-binary-tree-from-string | :lock: | | Medium |
| 537 | complex-number-multiplication | | :memo: | Medium |
| 538 | convert-bst-to-greater-tree | | :memo: | Easy |
| 539 | minimum-time-difference | | | Medium |
| 540 | single-element-in-a-sorted-array | | | Medium |
| 541 | reverse-string-ii | | :memo: | Easy |
| 542 | 01-matrix | | :memo: | Medium |
| 543 | diameter-of-binary-tree | | :memo: | Easy |
| 544 | output-contest-matches | :lock: | :memo: | Medium |
| 545 | boundary-of-binary-tree | :lock: | :memo: | Medium |
| 546 | remove-boxes | | :memo: | Hard |
| 547 | friend-circles | | :memo: | Medium |
| 548 | split-array-with-equal-sum | :lock: | :memo: | Medium |
| 549 | binary-tree-longest-consecutive-sequence-ii | :lock: | :memo: | Medium |
| 551 | student-attendance-record-i | | :memo: | Easy |
| 552 | student-attendance-record-ii | | :memo: | Hard |
| 553 | optimal-division | | :memo: | Medium |
| 554 | brick-wall | | :memo: | Medium |
| 555 | split-concatenated-strings | :lock: | :memo: | Medium |
| 556 | next-greater-element-iii | | :memo: | Medium |
| 557 | reverse-words-in-a-string-iii | | :memo: | Easy |
| 560 | subarray-sum-equals-k | | :memo: | Medium |
| 561 | array-partition-i | | :memo: | Easy |
| 562 | longest-line-of-consecutive-one-in-matrix | :lock: | :memo: | Medium |
| 563 | binary-tree-tilt | | :memo: | Easy |
| 564 | find-the-closest-palindrome | | :memo: | Hard |
| 565 | array-nesting | | :memo: | Medium |
| 566 | reshape-the-matrix | | :memo: | Easy |
| 567 | permutation-in-string | | :memo: | Medium |
| 568 | maximum-vacation-days | :lock: | :memo: | Hard |
| 572 | subtree-of-another-tree | | :memo: | Easy |
| 573 | squirrel-simulation | :lock: | :memo: | Medium |
| 575 | distribute-candies | | :memo: | Easy |
| 576 | out-of-boundary-paths | | :memo: | Medium |
| 581 | shortest-unsorted-continuous-subarray | | :memo: | Easy |
| 582 | kill-process | :lock: | :memo: | Medium |
| 583 | delete-operation-for-two-strings | | :memo: | Medium |
| 587 | erect-the-fence | | :memo: | Hard |
| 588 | design-in-memory-file-system | :lock: | :memo: | Hard |
| 591 | tag-validator | | :memo: | Hard |
| 592 | fraction-addition-and-subtraction | | :memo: | Medium |
| 593 | valid-square | | :memo: | Medium |
| 594 | longest-harmonious-subsequence | | :memo: | Easy |
| 598 | range-addition-ii | | :memo: | Easy |
| 599 | minimum-index-sum-of-two-lists | | :memo: | Easy |
| 600 | non-negative-integers-without-consecutive-ones | | :memo: | Hard |
| 604 | design-compressed-string-iterator | :lock: | :memo: | Easy |
| 605 | can-place-flowers | | :memo: | Easy |
| 606 | construct-string-from-binary-tree | | :memo: | Easy |
| 609 | find-duplicate-file-in-system | | :memo: | Medium |
| 611 | valid-triangle-number | | :memo: | Medium |
| 616 | add-bold-tag-in-string | :lock: | :memo: | Medium |
| 617 | merge-two-binary-trees | | :memo: | Easy |
| 621 | task-scheduler | | :memo: | Medium |
| 623 | add-one-row-to-tree | | :memo: | Medium |
| 624 | maximum-distance-in-arrays | :lock: | :memo: | Easy |
| 625 | minimum-factorization | :lock: | :memo: | Medium |
| 628 | maximum-product-of-three-numbers | | :memo: | Easy |
| 629 | k-inverse-pairs-array | | :memo: | Hard |
| 630 | course-schedule-iii | | :memo: | Hard |
| 631 | design-excel-sum-formula | :lock: | :memo: | Hard |
| 632 | smallest-range-covering-elements-from-k-lists | | :memo: | Hard |
| 633 | sum-of-square-numbers | | :memo: | Easy |
| 634 | find-the-derangement-of-an-array | :lock: | :memo: | Medium |
| 635 | design-log-storage-system | :lock: | :memo: | Medium |
| 636 | exclusive-time-of-functions | | :memo: | Medium |
| 637 | average-of-levels-in-binary-tree | | :memo: | Easy |
| 638 | shopping-offers | | :memo: | Medium |
| 639 | decode-ways-ii | | :memo: | Hard |
| 640 | solve-the-equation | | :memo: | Medium |
| 642 | design-search-autocomplete-system | :lock: | :memo: | Hard |
| 643 | maximum-average-subarray-i | | :memo: | Easy |
| 644 | maximum-average-subarray-ii | :lock: | :memo: | Hard |
| 645 | set-mismatch | | :memo: | Easy |
| 646 | maximum-length-of-pair-chain | | :memo: | Medium |
| 647 | palindromic-substrings | | :memo: | Medium |
| 648 | replace-words | | :memo: | Medium |
| 649 | dota2-senate | | :memo: | Medium |
| 650 | 2-keys-keyboard | | :memo: | Medium |
| 651 | 4-keys-keyboard | :lock: | :memo: | Medium |
| 652 | find-duplicate-subtrees | | :memo: | Medium |
| 653 | two-sum-iv-input-is-a-bst | | :memo: | Easy |
| 654 | maximum-binary-tree | | :memo: | Medium |
| 655 | print-binary-tree | | :memo: | Medium |
| 656 | coin-path | :lock: | :memo: | Hard |
| 657 | robot-return-to-origin | | :memo: | Easy |
| 658 | find-k-closest-elements | | :memo: | Medium |
| 659 | split-array-into-consecutive-subsequences | | :memo: | Medium |
| 660 | remove-9 | :lock: | :memo: | Hard |
| 661 | image-smoother | | :memo: | Easy |
| 662 | maximum-width-of-binary-tree | | :memo: | Medium |
| 663 | equal-tree-partition | :lock: | :memo: | Medium |
| 664 | strange-printer | | :memo: | Hard |
| 665 | non-decreasing-array | | :memo: | Easy |
| 666 | path-sum-iv | :lock: | :memo: | Medium |
| 667 | beautiful-arrangement-ii | | :memo: | Medium |
| 668 | kth-smallest-number-in-multiplication-table | | :memo: | Hard |
| 669 | trim-a-binary-search-tree | | :memo: | Easy |
| 670 | maximum-swap | | :memo: | Medium |
| 671 | second-minimum-node-in-a-binary-tree | | :memo: | Easy |
| 672 | bulb-switcher-ii | | :memo: | Medium |
| 673 | number-of-longest-increasing-subsequence | | :memo: | Medium |
| 674 | longest-continuous-increasing-subsequence | | :memo: | Easy |
| 675 | cut-off-trees-for-golf-event | | :memo: | Hard |
| 676 | implement-magic-dictionary | | :memo: | Medium |
| 677 | map-sum-pairs | | :memo: | Medium |
| 678 | valid-parenthesis-string | | :memo: | Medium |
| 679 | 24-game | | :memo: | Hard |
| 680 | valid-palindrome-ii | | :memo: | Easy |
| 681 | next-closest-time | :lock: | :memo: | Medium |
| 682 | baseball-game | | :memo: | Easy |
| 683 | k-empty-slots | :lock: | :memo: | Hard |
| 684 | redundant-connection | | :memo: | Medium |
| 685 | redundant-connection-ii | | :memo: | Hard |
| 686 | repeated-string-match | | :memo: | Easy |
| 687 | longest-univalue-path | | :memo: | Easy |
| 688 | knight-probability-in-chessboard | | :memo: | Medium |
| 689 | maximum-sum-of-3-non-overlapping-subarrays | | :memo: | Hard |
| 690 | employee-importance | | :memo: | Easy |
| 691 | stickers-to-spell-word | | :memo: | Hard |
| 692 | top-k-frequent-words | | :memo: | Medium |
| 693 | binary-number-with-alternating-bits | | :memo: | Easy |
| 694 | number-of-distinct-islands | :lock: | :memo: | Medium |
| 695 | max-area-of-island | | :memo: | Medium |
| 696 | count-binary-substrings | | :memo: | Easy |
| 697 | degree-of-an-array | | :memo: | Easy |
| 698 | partition-to-k-equal-sum-subsets | | :memo: | Medium |
| 699 | falling-squares | | :memo: | Hard |
| 711 | number-of-distinct-islands-ii | :lock: | :memo: | Hard |
| 712 | minimum-ascii-delete-sum-for-two-strings | | :memo: | Medium |
| 713 | subarray-product-less-than-k | | :memo: | Medium |
| 714 | best-time-to-buy-and-sell-stock-with-transaction-fee | | :memo: | Medium |
| 715 | range-module | | :memo: | Hard |
| 716 | max-stack | :lock: | :memo: | Easy |
| 717 | 1-bit-and-2-bit-characters | | :memo: | Easy |
| 718 | maximum-length-of-repeated-subarray | | :memo: | Medium |
| 719 | find-k-th-smallest-pair-distance | | :memo: | Hard |
| 720 | longest-word-in-dictionary | | :memo: | Easy |
| 721 | accounts-merge | | :memo: | Medium |
| 722 | remove-comments | | :memo: | Medium |
| 723 | candy-crush | :lock: | :memo: | Medium |
| 724 | find-pivot-index | | :memo: | Easy |
| 725 | split-linked-list-in-parts | | :memo: | Medium |
| 726 | number-of-atoms | | :memo: | Hard |
| 727 | minimum-window-subsequence | :lock: | :memo: | Hard |
| 728 | self-dividing-numbers | | :memo: | Easy |
| 729 | my-calendar-i | | :memo: | Medium |
| 730 | count-different-palindromic-subsequences | | :memo: | Hard |
| 731 | my-calendar-ii | | :memo: | Medium |
| 732 | my-calendar-iii | | :memo: | Hard |
| 733 | flood-fill | | :memo: | Easy |
| 734 | sentence-similarity | :lock: | :memo: | Easy |
| 735 | asteroid-collision | | :memo: | Medium |
| 736 | parse-lisp-expression | | :memo: | Hard |
| 737 | sentence-similarity-ii | :lock: | :memo: | Medium |
| 738 | monotone-increasing-digits | | :memo: | Medium |
| 739 | daily-temperatures | | :memo: | Medium |
| 740 | delete-and-earn | | :memo: | Medium |
| 741 | cherry-pickup | | :memo: | Hard |
| 742 | to-lower-case | | | Easy |
| 743 | closest-leaf-in-a-binary-tree | :lock: | :memo: | Medium |
| 744 | network-delay-time | | :memo: | Medium |
| 745 | find-smallest-letter-greater-than-target | | :memo: | Easy |
| 746 | prefix-and-suffix-search | | :memo: | Hard |
| 747 | min-cost-climbing-stairs | | :memo: | Easy |
| 748 | largest-number-at-least-twice-of-others | | :memo: | Easy |
| 749 | shortest-completing-word | | :memo: | Easy |
| 750 | contain-virus | | :memo: | Hard |
| 751 | number-of-corner-rectangles | :lock: | :memo: | Medium |
| 752 | ip-to-cidr | :lock: | :memo: | Easy |
| 753 | open-the-lock | | :memo: | Medium |
| 754 | cracking-the-safe | | :memo: | Hard |
| 755 | reach-a-number | | :memo: | Easy |
| 756 | pour-water | :lock: | :memo: | Medium |
| 757 | pyramid-transition-matrix | | :memo: | Medium |
| 758 | convert-binary-search-tree-to-sorted-doubly-linked-list | :lock: | :memo: | Medium |
| 759 | set-intersection-size-at-least-two | | :memo: | Hard |
| 760 | bold-words-in-string | :lock: | :memo: | Easy |
| 761 | employee-free-time | :lock: | :memo: | Hard |
| 762 | find-anagram-mappings | :lock: | :memo: | Easy |
| 763 | special-binary-string | | :memo: | Hard |
| 764 | n-ary-tree-level-order-traversal | | | Easy |
| 765 | serialize-and-deserialize-n-ary-tree | :lock: | | Hard |
| 766 | flatten-a-multilevel-doubly-linked-list | | | Medium |
| 767 | prime-number-of-set-bits-in-binary-representation | | :memo: | Easy |
| 768 | partition-labels | | :memo: | Medium |
| 769 | largest-plus-sign | | :memo: | Medium |
| 770 | couples-holding-hands | | :memo: | Hard |
| 771 | encode-n-ary-tree-to-binary-tree | :lock: | | Hard |
| 772 | construct-quad-tree | | | Medium |
| 773 | quad-tree-intersection | | | Easy |
| 774 | maximum-depth-of-n-ary-tree | | :memo: | Easy |
| 775 | n-ary-tree-preorder-traversal | | :memo: | Easy |
| 776 | n-ary-tree-postorder-traversal | | :memo: | Easy |
| 777 | toeplitz-matrix | | :memo: | Easy |
| 778 | reorganize-string | | :memo: | Medium |
| 779 | max-chunks-to-make-sorted-ii | | :memo: | Hard |
| 780 | max-chunks-to-make-sorted | | :memo: | Medium |
| 781 | basic-calculator-iv | | :memo: | Hard |
| 782 | jewels-and-stones | | :memo: | Easy |
| 783 | search-in-a-binary-search-tree | | | Easy |
| 784 | insert-into-a-binary-search-tree | | :memo: | Medium |
| 785 | basic-calculator-iii | :lock: | | Hard |
| 786 | search-in-a-sorted-array-of-unknown-size | :lock: | | Medium |
| 787 | sliding-puzzle | | :memo: | Hard |
| 788 | minimize-max-distance-to-gas-station | :lock: | :memo: | Hard |
| 789 | kth-largest-element-in-a-stream | | | Easy |
| 790 | global-and-local-inversions | | :memo: | Medium |
| 791 | split-bst | :lock: | :memo: | Medium |
| 792 | binary-search | | :memo: | Easy |
| 793 | swap-adjacent-in-lr-string | | :memo: | Medium |
| 794 | swim-in-rising-water | | :memo: | Hard |
| 795 | k-th-symbol-in-grammar | | :memo: | Medium |
| 796 | reaching-points | | :memo: | Hard |
| 797 | rabbits-in-forest | | :memo: | Medium |
| 798 | transform-to-chessboard | | :memo: | Hard |
| 799 | minimum-distance-between-bst-nodes | | :memo: | Easy |
| 800 | letter-case-permutation | | :memo: | Easy |
| 801 | is-graph-bipartite | | :memo: | Medium |
| 802 | k-th-smallest-prime-fraction | | :memo: | Hard |
| 803 | cheapest-flights-within-k-stops | | :memo: | Medium |
| 804 | rotated-digits | | :memo: | Easy |
| 805 | escape-the-ghosts | | :memo: | Medium |
| 806 | domino-and-tromino-tiling | | :memo: | Medium |
| 807 | custom-sort-string | | :memo: | Medium |
| 808 | number-of-matching-subsequences | | :memo: | Medium |
| 809 | preimage-size-of-factorial-zeroes-function | | :memo: | Hard |
| 810 | valid-tic-tac-toe-state | | :memo: | Medium |
| 811 | number-of-subarrays-with-bounded-maximum | | :memo: | Medium |
| 812 | rotate-string | | :memo: | Easy |
| 813 | all-paths-from-source-to-target | | :memo: | Medium |
| 814 | smallest-rotation-with-highest-score | | :memo: | Hard |
| 815 | champagne-tower | | :memo: | Medium |
| 816 | design-hashset | | | Easy |
| 817 | design-hashmap | | | Easy |
| 818 | similar-rgb-color | :lock: | :memo: | Easy |
| 819 | minimum-swaps-to-make-sequences-increasing | | :memo: | Medium |
| 820 | find-eventual-safe-states | | :memo: | Medium |
| 821 | bricks-falling-when-hit | | :memo: | Hard |
| 822 | unique-morse-code-words | | :memo: | Easy |
| 823 | split-array-with-same-average | | :memo: | Hard |
| 824 | number-of-lines-to-write-string | | :memo: | Easy |
| 825 | max-increase-to-keep-city-skyline | | :memo: | Medium |
| 826 | soup-servings | | :memo: | Medium |
| 827 | expressive-words | | :memo: | Medium |
| 828 | chalkboard-xor-game | | :memo: | Hard |
| 829 | subdomain-visit-count | | :memo: | Easy |
| 830 | largest-triangle-area | | :memo: | Easy |
| 831 | largest-sum-of-averages | | :memo: | Medium |
| 832 | binary-tree-pruning | | :memo: | Medium |
| 833 | bus-routes | | :memo: | Hard |
| 834 | ambiguous-coordinates | | :memo: | Medium |
| 835 | linked-list-components | | :memo: | Medium |
| 836 | race-car | | :memo: | Hard |
| 837 | most-common-word | | :memo: | Easy |
| 838 | design-linked-list | | | Easy |
| 839 | short-encoding-of-words | | :memo: | Medium |
| 841 | shortest-distance-to-a-character | | :memo: | Easy |
| 842 | card-flipping-game | | :memo: | Medium |
| 843 | binary-trees-with-factors | | :memo: | Medium |
| 850 | insert-into-a-cyclic-sorted-list | :lock: | | Medium |
| 851 | goat-latin | | :memo: | Easy |
| 852 | friends-of-appropriate-ages | | :memo: | Medium |
| 853 | most-profit-assigning-work | | :memo: | Medium |
| 854 | making-a-large-island | | :memo: | Hard |
| 855 | unique-letter-string | | :memo: | Hard |
| 856 | consecutive-numbers-sum | | :memo: | Hard |
| 857 | positions-of-large-groups | | :memo: | Easy |
| 858 | masking-personal-information | | :memo: | Medium |
| 859 | design-circular-deque | | | Medium |
| 860 | design-circular-queue | | | Medium |
| 861 | flipping-an-image | | :memo: | Easy |
| 862 | find-and-replace-in-string | | :memo: | Medium |
| 863 | sum-of-distances-in-tree | | :memo: | Hard |
| 864 | image-overlap | | :memo: | Medium |
| 865 | robot-room-cleaner | :lock: | :memo: | Hard |
| 866 | rectangle-overlap | | :memo: | Easy |
| 867 | new-21-game | | :memo: | Medium |
| 868 | push-dominoes | | :memo: | Medium |
| 869 | similar-string-groups | | :memo: | Hard |
| 870 | magic-squares-in-grid | | :memo: | Easy |
| 871 | keys-and-rooms | | :memo: | Medium |
| 872 | split-array-into-fibonacci-sequence | | :memo: | Medium |
| 873 | guess-the-word | | :memo: | Hard |
| 874 | backspace-string-compare | | :memo: | Easy |
| 875 | longest-mountain-in-array | | :memo: | Medium |
| 876 | hand-of-straights | | :memo: | Medium |
| 877 | shortest-path-visiting-all-nodes | | :memo: | Hard |
| 878 | shifting-letters | | :memo: | Medium |
| 879 | maximize-distance-to-closest-person | | :memo: | Easy |
| 880 | rectangle-area-ii | | :memo: | Hard |
| 881 | loud-and-rich | | :memo: | Medium |
| 882 | peak-index-in-a-mountain-array | | :memo: | Easy |
| 883 | car-fleet | | :memo: | Medium |
| 884 | k-similar-strings | | :memo: | Hard |
| 885 | exam-room | | :memo: | Medium |
| 886 | score-of-parentheses | | :memo: | Medium |
| 887 | minimum-cost-to-hire-k-workers | | :memo: | Hard |
| 888 | mirror-reflection | | :memo: | Medium |
| 889 | buddy-strings | | :memo: | Easy |
| 890 | lemonade-change | | :memo: | Easy |
| 891 | score-after-flipping-matrix | | :memo: | Medium |
| 892 | shortest-subarray-with-sum-at-least-k | | :memo: | Hard |
| 893 | all-nodes-distance-k-in-binary-tree | | :memo: | Medium |
| 894 | random-pick-with-blacklist | | :memo: | Hard |
| 895 | shortest-path-to-get-all-keys | | :memo: | Hard |
| 896 | smallest-subtree-with-all-the-deepest-nodes | | :memo: | Medium |
| 897 | prime-palindrome | | :memo: | Medium |
| 898 | transpose-matrix | | :memo: | Easy |
| 899 | binary-gap | | :memo: | Easy |
| 900 | reordered-power-of-2 | | :memo: | Medium |
| 901 | advantage-shuffle | | :memo: | Medium |
| 902 | minimum-number-of-refueling-stops | | :memo: | Hard |
| 903 | implement-rand10-using-rand7 | | :memo: | Medium |
| 904 | leaf-similar-trees | | :memo: | Easy |
| 905 | length-of-longest-fibonacci-subsequence | | :memo: | Medium |
| 906 | walking-robot-simulation | | :memo: | Easy |
| 907 | koko-eating-bananas | | :memo: | Medium |
| 908 | middle-of-the-linked-list | | :memo: | Easy |
| 909 | stone-game | | :memo: | Medium |
| 910 | nth-magical-number | | :memo: | Hard |
| 911 | profitable-schemes | | :memo: | Hard |
| 912 | random-pick-with-weight | | :memo: | Medium |
| 913 | random-flip-matrix | | :memo: | Medium |
| 914 | random-point-in-non-overlapping-rectangles | | :memo: | Medium |
| 915 | generate-random-point-in-a-circle | | :memo: | Medium |
| 916 | decoded-string-at-index | | :memo: | Medium |
| 917 | boats-to-save-people | | :memo: | Medium |
| 918 | reachable-nodes-in-subdivided-graph | | :memo: | Hard |
| 919 | projection-area-of-3d-shapes | | :memo: | Easy |
| 920 | uncommon-words-from-two-sentences | | :memo: | Easy |
| 921 | spiral-matrix-iii | | :memo: | Medium |
| 922 | possible-bipartition | | :memo: | Medium |
| 923 | super-egg-drop | | :memo: | Hard |
| 924 | fair-candy-swap | | :memo: | Easy |
| 925 | construct-binary-tree-from-preorder-and-postorder-traversal | | :memo: | Medium |
| 926 | find-and-replace-pattern | | :memo: | Medium |
| 927 | sum-of-subsequence-widths | | :memo: | Hard |
| 928 | surface-area-of-3d-shapes | | :memo: | Easy |
| 929 | groups-of-special-equivalent-strings | | :memo: | Easy |
| 930 | all-possible-full-binary-trees | | :memo: | Medium |
| 931 | maximum-frequency-stack | | :memo: | Hard |
| 932 | monotonic-array | | :memo: | Easy |
| 933 | increasing-order-search-tree | | :memo: | Easy |
| 934 | bitwise-ors-of-subarrays | | :memo: | Medium |
| 935 | orderly-queue | | :memo: | Hard |
| 936 | rle-iterator | | :memo: | Medium |
| 937 | online-stock-span | | :memo: | Medium |
| 938 | numbers-at-most-n-given-digit-set | | :memo: | Hard |
| 939 | valid-permutations-for-di-sequence | | :memo: | Hard |
| 940 | fruit-into-baskets | | :memo: | Medium |
| 941 | sort-array-by-parity | | :memo: | Easy |
| 942 | super-palindromes | | :memo: | Hard |
| 943 | sum-of-subarray-minimums | | :memo: | Medium |
| 944 | smallest-range-i | | :memo: | Easy |
| 945 | snakes-and-ladders | | :memo: | Medium |
| 946 | smallest-range-ii | | :memo: | Medium |
| 947 | online-election | | :memo: | Medium |
| 948 | sort-an-array | | | Medium |
| 949 | cat-and-mouse | | :memo: | Hard |
| 950 | x-of-a-kind-in-a-deck-of-cards | | :memo: | Easy |
| 951 | partition-array-into-disjoint-intervals | | :memo: | Medium |
| 952 | word-subsets | | :memo: | Medium |
| 953 | reverse-only-letters | | :memo: | Easy |
| 954 | maximum-sum-circular-subarray | | :memo: | Medium |
| 955 | complete-binary-tree-inserter | | :memo: | Medium |
| 956 | number-of-music-playlists | | :memo: | Hard |
| 957 | minimum-add-to-make-parentheses-valid | | :memo: | Medium |
| 958 | sort-array-by-parity-ii | | :memo: | Easy |
| 959 | 3sum-with-multiplicity | | :memo: | Medium |
| 960 | minimize-malware-spread | | :memo: | Hard |
| 961 | long-pressed-name | | :memo: | Easy |
| 962 | flip-string-to-monotone-increasing | | :memo: | Medium |
| 963 | three-equal-parts | | :memo: | Hard |
| 964 | minimize-malware-spread-ii | | :memo: | Hard |
| 965 | unique-email-addresses | | :memo: | Easy |
| 966 | binary-subarrays-with-sum | | :memo: | Medium |
| 967 | minimum-falling-path-sum | | :memo: | Medium |
| 968 | beautiful-array | | :memo: | Medium |
| 969 | number-of-recent-calls | | :memo: | Easy |
| 971 | shortest-bridge | | :memo: | Medium |
| 972 | knight-dialer | | :memo: | Medium |
| 973 | stamping-the-sequence | | :memo: | Hard |
| 974 | reorder-log-files | | :memo: | Easy |
| 975 | range-sum-of-bst | | :memo: | Easy |
| 976 | minimum-area-rectangle | | :memo: | Medium |
| 977 | distinct-subsequences-ii | | :memo: | Hard |
| 978 | valid-mountain-array | | :memo: | Easy |
| 979 | di-string-match | | :memo: | Easy |
| 980 | find-the-shortest-superstring | | :memo: | Hard |
| 981 | delete-columns-to-make-sorted | | :memo: | Easy |
| 982 | minimum-increment-to-make-array-unique | | :memo: | Medium |
| 983 | validate-stack-sequences | | :memo: | Medium |
| 984 | most-stones-removed-with-same-row-or-column | | :memo: | Medium |
| 985 | bag-of-tokens | | :memo: | Medium |
| 986 | largest-time-for-given-digits | | :memo: | Easy |
| 987 | reveal-cards-in-increasing-order | | :memo: | Medium |
| 988 | flip-equivalent-binary-trees | | :memo: | Medium |
| 989 | largest-component-size-by-common-factor | | :memo: | Hard |
| 990 | verifying-an-alien-dictionary | | :memo: | Easy |
| 991 | array-of-doubled-pairs | | :memo: | Medium |
| 992 | delete-columns-to-make-sorted-ii | | :memo: | Medium |
| 993 | tallest-billboard | | :memo: | Hard |
| 994 | prison-cells-after-n-days | | :memo: | Medium |
| 998 | check-completeness-of-a-binary-tree | | :memo: | Medium |
| 999 | regions-cut-by-slashes | | :memo: | Medium |
| 1000 | delete-columns-to-make-sorted-iii | | :memo: | Hard |
| 1001 | n-repeated-element-in-size-2n-array | | :memo: | Easy |
| 1002 | maximum-width-ramp | | :memo: | Medium |
| 1003 | minimum-area-rectangle-ii | | :memo: | Medium |
| 1004 | least-operators-to-express-number | | :memo: | Hard |
| 1005 | univalued-binary-tree | | :memo: | Easy |
| 1006 | vowel-spellchecker | | :memo: | Medium |
| 1007 | numbers-with-same-consecutive-differences | | :memo: | Medium |
| 1008 | binary-tree-cameras | | :memo: | Hard |
| 1009 | pancake-sorting | | :memo: | Medium |
| 1010 | powerful-integers | | :memo: | Easy |
| 1011 | flip-binary-tree-to-match-preorder-traversal | | :memo: | Medium |
| 1012 | equal-rational-numbers | | :memo: | Hard |
| 1013 | fibonacci-number | | :memo: | Easy |
| 1014 | k-closest-points-to-origin | | :memo: | Medium |
| 1016 | subarray-sums-divisible-by-k | | :memo: | Medium |
| 1017 | odd-even-jump | | :memo: | Hard |
| 1018 | largest-perimeter-triangle | | :memo: | Easy |
| 1019 | squares-of-a-sorted-array | | :memo: | Easy |
| 1020 | longest-turbulent-subarray | | :memo: | Medium |
| 1021 | distribute-coins-in-binary-tree | | :memo: | Medium |
| 1022 | unique-paths-iii | | :memo: | Hard |
| 1023 | time-based-key-value-store | | :memo: | Medium |
| 1024 | triples-with-bitwise-and-equal-to-zero | | | Hard |
| 1025 | minimum-cost-for-tickets | | :memo: | Medium |
| 1026 | string-without-aaa-or-bbb | | :memo: | Medium |
| 1027 | sum-of-even-numbers-after-queries | | :memo: | Easy |
| 1028 | interval-list-intersections | | :memo: | Medium |
| 1029 | vertical-order-traversal-of-a-binary-tree | | :memo: | Medium |
| 1030 | smallest-string-starting-from-leaf | | :memo: | Medium |
| 1031 | add-to-array-form-of-integer | | :memo: | Easy |
| 1032 | satisfiability-of-equality-equations | | :memo: | Medium |
| 1033 | broken-calculator | | :memo: | Medium |
| 1034 | subarrays-with-k-different-integers | | :memo: | Hard |
| 1035 | cousins-in-binary-tree | | :memo: | Easy |
| 1036 | rotting-oranges | | :memo: | Easy |
| 1037 | minimum-number-of-k-consecutive-bit-flips | | :memo: | Hard |
| 1038 | number-of-squareful-arrays | | :memo: | Hard |
| 1039 | find-the-town-judge | | | Easy |
| 1040 | maximum-binary-tree-ii | | | Medium |
| 1041 | available-captures-for-rook | | | Easy |
| 1042 | minimum-cost-to-merge-stones | | | Hard |
| 1043 | grid-illumination | | | Hard |
| 1044 | find-common-characters | | | Easy |
| 1045 | check-if-word-is-valid-after-substitutions | | | Medium |
| 1046 | max-consecutive-ones-iii | | | Medium |
| 1047 | maximize-sum-of-array-after-k-negations | | | Easy |
| 1048 | clumsy-factorial | | | Medium |
| 1049 | minimum-domino-rotations-for-equal-row | | :memo: | Medium |
| 1050 | construct-binary-search-tree-from-preorder-traversal | | :memo: | Medium |
| 1051 | shortest-way-to-form-string | :lock: | | Medium |
| 1052 | campus-bikes | :lock: | | Medium |
| 1053 | minimize-rounding-error-to-meet-target | :lock: | | Medium |
| 1054 | complement-of-base-10-integer | | | Easy |
| 1055 | pairs-of-songs-with-total-durations-divisible-by-60 | | | Easy |
| 1056 | capacity-to-ship-packages-within-d-days | | | Medium |
| 1057 | numbers-with-repeated-digits | | | Hard |
| 1058 | lexicographically-smallest-equivalent-string | :lock: | | Medium |
| 1059 | missing-element-in-sorted-array | :lock: | :memo: | Medium |
| 1060 | longest-repeating-substring | :lock: | :memo: | Medium |
| 1061 | number-of-valid-subarrays | :lock: | | Hard |
| 1062 | partition-array-into-three-parts-with-equal-sum | | | Easy |
| 1063 | best-sightseeing-pair | | | Medium |
| 1064 | smallest-integer-divisible-by-k | | | Medium |
| 1065 | binary-string-with-substrings-representing-1-to-n | Python | | Medium |
| 1066 | fixed-point | :lock: | | Easy |
| 1067 | campus-bikes-ii | :lock: | | Medium |
| 1068 | digit-count-in-range | :lock: | | Hard |
| 1069 | confusing-number | :lock: | | Easy |
| 1070 | convert-to-base-2 | | | Medium |
| 1071 | binary-prefix-divisible-by-5 | | | Easy |
| 1072 | next-greater-node-in-linked-list | | | Medium |
| 1073 | number-of-enclaves | | | Medium |
| 1074 | high-five | :lock: | | Easy |
| 1075 | index-pairs-of-a-string | :lock: | | Easy |
| 1076 | brace-expansion | :lock: | | Medium |
| 1077 | confusing-number-ii | :lock: | | Hard |
| 1078 | remove-outermost-parentheses | | | Easy |
| 1079 | sum-of-root-to-leaf-binary-numbers | | | Easy |
| 1080 | camelcase-matching | | | Medium |
| 1081 | video-stitching | | | Medium |
| 1082 | sum-of-digits-in-the-minimum-number | :lock: | | Easy |
| 1083 | two-sum-less-than-k | :lock: | | Easy |
| 1084 | find-k-length-substrings-with-no-repeated-characters | :lock: | | Medium |
| 1085 | the-earliest-moment-when-everyone-become-friends | :lock: | | Medium |
| 1086 | divisor-game | | | Easy |
| 1087 | longest-arithmetic-sequence | | | Medium |
| 1088 | number-of-days-in-a-month | :lock: | | Easy |
| 1089 | remove-vowels-from-a-string | :lock: | | Easy |
| 1090 | armstrong-number | :lock: | | Easy |
| 1091 | maximum-average-subtree | :lock: | | Medium |
| 1092 | maximum-difference-between-node-and-ancestor | | | Medium |
| 1093 | recover-a-tree-from-preorder-traversal | | | Hard |
| 1094 | matrix-cells-in-distance-order | | | Easy |
| 1095 | two-city-scheduling | | :memo: | Easy |
| 1096 | maximum-sum-of-two-non-overlapping-subarrays | | | Medium |
| 1097 | stream-of-characters | | | Hard |
| 1098 | largest-unique-number | :lock: | | Easy |
| 1099 | path-with-maximum-minimum-value | :lock: | | Medium |
| 1100 | connecting-cities-with-minimum-cost | :lock: | | Medium |
| 1101 | parallel-courses | :lock: | | Hard |
| 1102 | check-if-a-number-is-majority-element-in-a-sorted-array | :lock: | | Easy |
| 1103 | moving-stones-until-consecutive | | | Easy |
| 1104 | coloring-a-border | | | Medium |
| 1105 | uncrossed-lines | | | Medium |
| 1106 | escape-a-large-maze | | | Hard |
| 1107 | minimum-swaps-to-group-all-1s-together | :lock: | | Medium |
| 1108 | analyze-user-website-visit-pattern | :lock: | | Medium |
| 1111 | minimum-score-triangulation-of-polygon | | | Medium |
| 1112 | find-words-that-can-be-formed-by-characters | | | Easy |
| 1113 | moving-stones-until-consecutive-ii | | | Medium |
| 1114 | binary-search-tree-to-greater-sum-tree | | | Medium |
| 1115 | valid-boomerang | | | Easy |
| 1116 | maximum-level-sum-of-a-binary-tree | | | Medium |
| 1117 | as-far-from-land-as-possible | | | Medium |
| 1118 | divide-array-into-increasing-sequences | :lock: | | Hard |
| 1119 | robot-bounded-in-circle | | | Medium |
| 1120 | flower-planting-with-no-adjacent | | | Easy |
| 1121 | partition-array-for-maximum-sum | | | Medium |
| 1122 | longest-duplicate-substring | | :memo: | Hard |
| 1124 | string-transforms-into-another-string | :lock: | | Hard |
| 1127 | last-stone-weight | | | Easy |
| 1128 | remove-all-adjacent-duplicates-in-string | | :memo: | Easy |
| 1129 | longest-string-chain | | | Medium |
| 1130 | last-stone-weight-ii | | | Medium |
| 1133 | last-substring-in-lexicographical-order | | | Hard |
| 1137 | height-checker | | | Easy |
| 1138 | grumpy-bookstore-owner | | | Medium |
| 1139 | previous-permutation-with-one-swap | | | Medium |
| 1140 | distant-barcodes | | | Medium |
| 1145 | number-of-submatrices-that-sum-to-target | | | Hard |
| 1146 | greatest-common-divisor-of-strings | | | Easy |
| 1147 | flip-columns-for-maximum-number-of-equal-rows | | | Medium |
| 1148 | adding-two-negabinary-numbers | | | Medium |
| 1156 | occurrences-after-bigram | | | Easy |
| 1157 | insufficient-nodes-in-root-to-leaf-paths | | | Medium |
| 1159 | smallest-subsequence-of-distinct-characters | | | Medium |
| 1160 | letter-tile-possibilities | | | Medium |
| 1168 | duplicate-zeros | | | Easy |
| 1169 | largest-values-from-labels | | | Medium |
| 1170 | shortest-common-supersequence | | | Hard |
| 1171 | shortest-path-in-binary-matrix | | | Medium |
| 1183 | statistics-from-a-large-sample | | | Medium |
| 1184 | car-pooling | | | Medium |
| 1185 | find-in-mountain-array | | | Hard |
| 1188 | brace-expansion-ii | | | Hard |
| 1194 | path-in-zigzag-labelled-binary-tree | | | Medium |
| 1195 | distribute-candies-to-people | | :memo: | Easy |
| 1196 | filling-bookcase-shelves | | | Medium |
| 1197 | parsing-a-boolean-expression | | | Hard |
| 1205 | defanging-an-ip-address | | | Easy |
| 1206 | corporate-flight-bookings | | | Medium |
| 1207 | delete-nodes-and-return-forest | | | Medium |
| 1208 | maximum-nesting-depth-of-two-valid-parentheses-strings | | | Medium |
| 1217 | relative-sort-array | | | Easy |
| 1218 | lowest-common-ancestor-of-deepest-leaves | | | Medium |
| 1219 | longest-well-performing-interval | | | Medium |
| 1220 | smallest-sufficient-team | | | Hard |
| 1227 | number-of-equivalent-domino-pairs | | | Easy |
| 1228 | minimum-cost-tree-from-leaf-values | | | Medium |
| 1229 | shortest-path-with-alternating-colors | | | Medium |
| 1230 | maximum-of-absolute-value-expression | | | Medium |
| 1236 | n-th-tribonacci-number | | :memo: | Easy |
| 1238 | alphabet-board-path | | | Medium |
| 1239 | largest-1-bordered-square | | | Medium |
| 1240 | stone-game-ii | | | Medium |
| 1247 | decrease-elements-to-make-array-zigzag | | | Medium |
| 1248 | binary-tree-coloring-game | | | Medium |
| 1249 | snapshot-array | | | Medium |
| 1250 | longest-common-subsequence | | | Medium |
| 1251 | longest-chunked-palindrome-decomposition | | | Hard |
| 1260 | day-of-the-year | | | Easy |
| 1261 | swap-for-longest-repeated-character-substring | | | Medium |
| 1262 | online-majority-element-in-subarray | | | Hard |
| 1263 | number-of-dice-rolls-with-target-sum | | | Medium |