Problem Statement:
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.
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 <= 10^9
1 <= nums.length <= 10^5
1 <= nums[i] <= 10^4
Solution:
class Solution {
public int minSubArrayLen(int target, int[] nums) {
int start = 0;
int end = 0;
int minLength = Integer.MAX_VALUE;
int newTarget = target;
while(end < nums.length){
newTarget = newTarget - nums[end];
while(newTarget <= 0){
int windowSize = end - start + 1;
minLength = Math.min(minLength, windowSize);
newTarget += nums[start];
start++;
}
end++;
}
return minLength == Integer.MAX_VALUE ? 0 : minLength;
}
}