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.
If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log n).
Credits:
Special thanks to @Freezen for adding this problem and creating all test cases.
典型two-pointer题：
class Solution { public: int minSubArrayLen(int s, vector<int>& nums) { int minlen = INT_MAX; int len = nums.size(); int p = 0; int q = 0; int csum = 0; while (q < len) { csum += nums[q]; while (csum >= s) { minlen = min(minlen, q - p + 1); csum -=nums[p++]; } q++; } return minlen == INT_MAX ? 0 : minlen; } };
LeetCode Minimum Size Subarray Sum
原文：http://www.cnblogs.com/lailailai/p/4503704.html