Minimum Size Subarray Sum
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# LeetCode #209: Minimum Size Subarray Sum (C/C++).

medium

source: https://leetcode.com/problems/minimum-size-subarray-sum/
C/C++ Solution to LeetCode problem 209. Minimum Size Subarray Sum.

## Problem

Given an array of positive integers nums and a positive integer target, return the minimal length of a subarray whose sum is greater than or equal to target. If there is no such subarray, return 0 instead.

## Examples

### Example 1:

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

### Example 2:

Input: target = 4, nums = [1,4,4]
Output: 1

### Example 3:

Input: target = 11, nums = [1,1,1,1,1,1,1,1]
Output: 0

## Constraints

• 1 <= target <= 109
• 1 <= nums.length <= 105
• 1 <= nums[i] <= 104

## Solution

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 class Solution { public: int minSubArrayLen(int target, vector<int>& nums) { int min = nums.size() + 1; int sum = 0; int start = 0; for(int i=0; i<nums.size(); i++) { sum += nums[i]; while (sum >= target && start < i) { if (sum - nums[start] >= target) { sum -= nums[start]; start += 1; } else break; } int s = (i+1) - start; if (sum >= target && s < min) min = s; } return min == nums.size() + 1 ? 0 : min; } };