Leetcode: Minimum Size Subarray Sum

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.

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class Solution {
public:
int minSubArrayLen(int s, vector<int>& nums) {
int left, right, min = 0xfffffff, sum = 0;
int n = nums.size();

if (n == 0) return 0;

sum = nums[0];
left = 0;
right = 0;
while (1) {
if (sum < s) {
right++;
if (right >= n) {
break;
}
sum += nums[right];
} else {
min = min > (right - left + 1) ? right - left + 1 : min;

if (min == 1) return 1;// Game Over

sum -= nums[left];
left++;
}
}

return min == 0xfffffff ? 0 : min;
}
};