LeetCode [209] Minimum Size Subarray Sum

 209. Minimum Size Subarray Sum

Medium

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.

Example: 

Input: s = 7, nums = [2,3,1,2,4,3]
Output: 2
Explanation: the subarray [4,3] has the minimal length under the problem constraint.

Follow up:

If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log n). 

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//C++: method1 4ms class Solution { public: int minSubArrayLen(int s, vector<int>& nums) { int n = nums.size(), l = 0, r = 0, sum = 0, ret = INT_MAX; bool found = false; while(r<n){ sum += nums[r++]; while(sum-nums[l]>=s){ sum -= nums[l++]; } if(sum>=s){ ret = min(ret, r-l); found = true; } } return found?ret:0; } };