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.
A subarray is a contiguous non-empty sequence of elements within an array.
Example 1:
Input: nums = [2,3,1,2,4,3], target = 7
Output: 2
Explanation: The subarray [4,3] has the minimal length under the constraint of sum >= 7.
Example 2:
Input: nums = [1,4,4], target = 4
Output: 1
Explanation: The subarray [4] has the minimal length under the constraint of sum >= 4.
Example 3:
Input: nums = [1,1,1,1,1,1,1,1], target = 11
Output: 0
Explanation: The total sum is 8, which is less than 11. No subarray satisfies the constraint.
1 <= target <= 10^91 <= nums.length <= 10^51 <= nums[i] <= 10^4