Given an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the sum ≥ s. If there isn’t one, return 0 instead.
For example, given the array [2,3,1,2,4,3] and s = 7, the subarray [4,3] has the minimal length under the problem constraint.
classSolution { public: intminSubArrayLen(int s, vector<int>& nums){ int len = nums.size(); if(len == 0) return0; int minlen = INT_MAX; int sum = 0; int left = 0; int right = -1; while(right < len) { while(sum < s && right < len) sum += nums[++right]; if(sum >= s) { minlen = minlen < right - left + 1 ? minlen : right - left + 1; sum -= nums[left++]; } } return minlen > len ? 0 : minlen; } };