209. Minimum Size Subarray Sum

Medium

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 <= 10⁹
1 <= nums.length <= 10⁵
1 <= nums[i] <= 10⁴

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