/*
Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous 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.
*/

public class Solution {
    public int minSubArrayLen(int s, int[] nums) {
        int r = 0;
        int l = 0;
        int sum = 0;
        int res = Integer.MAX_VALUE;
        while (r < nums.length) {
            sum += nums[r++];
            while (sum >= s) {
                res = Math.min(res, r - l);
                sum -= nums[l++];
            }
        }
        return res == Integer.MAX_VALUE ? 0 : res;
    }
}
