array Subarray Sum Equals K Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k.Example 1:Input:nums = [1,1,1], k = 2

binary search 33. Search in Rotated Sorted Array Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,

subarray 525. Contiguous Array Given a binary array, find the maximum length of a contiguous subarray with equal number of 0 and 1.Example 1: Input: [0,1] Output: 2 Explanation: [0, 1] is the longest contiguous