Minimum Size Subarray Sum

Solution

Iterate right

def minSubArrayLen(self, s: int, nums: List[int]) -> int:
    n = len(nums)
    csum = 0
    left = 0
    res = sys.maxsize
    for right in range(n):
        csum += nums[right]

        while csum >= s and left < n:
            res = min(res, right - left + 1)
            csum -= nums[left]
            left += 1

    if res == sys.maxsize:
        return 0
    else:
        return res

Iterate left

def minSubArrayLen(self, s: int, nums: List[int]) -> int:
    n = len(nums)
    csum = 0
    right = 0
    res = sys.maxsize
    for left in range(n):
        while csum < s and right < n:
            csum += nums[right]
            right += 1
        if csum >= s:
            res = min(res, right - left)
        csum -= nums[left]

    if res == sys.maxsize:
        return 0
    else:
        return res