minimum_size_subarray_sum.py

def minsubarraysum(target: int, nums: list[int]) -> int:
    """
    Returns the length of the shortest contiguous subarray
     in nums whose sum is at least target.

    Examples:
        >>> minsubarraysum(7, [2, 3, 1, 2, 4, 3])
        2
        >>> minsubarraysum(7, [2, 3, -1, 2, 4, -3])
        4
        >>> minsubarraysum(11, [1, 1, 1, 1, 1, 1, 1, 1])
        0
    """
    n = len(nums)
    if n == 0:
        return 0

    left = 0
    right = 0
    curr_sum = 0
    min_len = float("inf")

    while right < n:
        curr_sum += nums[right]
        while curr_sum >= target:
            min_len = min(min_len, right - left + 1)
            curr_sum -= nums[left]
            left += 1
        right += 1

    return int(min_len) if min_len != float("inf") else 0