leetcode209. Minimum Size Subarray Sum

209. Minimum Size Subarray Sum

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.

解法

public class Solution {
public int minSubArrayLen(int s, int[] nums) {
if (nums == null || nums.length == 0) {
return 0;
}

int sum = 0, len = 0, minLen = Integer.MAX_VALUE;
for (int i = 0; i < nums.length; i++) {
sum += nums[i];
len++;
if (sum >= s) {
if (len < minLen) {
minLen = len;
}
i = i - len + 1;
len = 0;
sum = 0;
}
}

return minLen != Integer.MAX_VALUE ? minLen : 0;
}
}