Minimum Size Subarray Sum

標籤：

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.

 

Analyse: Two pointers.

Runtime: 8ms.

 1 class Solution { 2 public: 3     int minSubArrayLen(int s, vector<int>& nums) { 4         int start = 0, end = 0; 5         int result = INT_MAX, sum = 0; 6         bool flag = false; 7         for(; end < nums.size(); end++){ 8             sum += nums[end]; 9             while(sum >= s){10                 flag = true;11                 result = min(result, end - start + 1);12                 sum -= nums[start++];13             }14         }15         return flag ? result : 0;16     }17 };

 

Minimum Size Subarray Sum