README.md

An easy dynamic programming problem.

Given array arr, we can define another array dp, dp[i] means the length of longest increasing subsequence when the last item is arr[i]. How to get dp[i]? We can get it by enumerating from index=0 to index=i-1(for instance j), and check the value of arr[j] and arr[i], if arr[i] > arr[j], then dp[i]=max(dp[i],dp[j]+1).

The algorithm above runs in O(n2) complexity, how to improve it to O(n log n) time complexity? Use binary search, see the code in detail. My runtime beats 100.00% of javascript submissions.