Minimum Size Subarray Sum

Medium Minimum Size Subarray Sum

22%

Accepted

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 -1 instead.

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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.

Challenge

If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log n).

public class Solution {
    /**
     * @param nums: an array of integers
     * @param s: an integer
     * @return: an integer representing the minimum size of subarray
     */
    public int minimumSize(int[] nums, int s) {
        // write your code here
       
        int sum = 0, len = Integer.MAX_VALUE, start = 0, end = 0;
       
        while(end < nums.length){
            while(end < nums.length && sum < s){
                sum += nums[end++];
            }
           
            while(sum >= s){
                len = Math.min(len, end - start);
                sum -= nums[start++];
            }
        }
        return len == Integer.MAX_VALUE ? -1 : len;
    }
}