Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn’t one, return 0 instead.
Input: s = 7, nums = [2,3,1,2,4,3]
Explanation: the subarray [4,3] has the minimal length under the problem constraint.
If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log n).
Setting 2 points : right and left. When sum less than the target s, right will plus. When sum larger than the target s, left will plus. Stopping the while loop, until the right of point equal nums length.