题目：
    209.长度最小的子数组

    思路：
    找出和大于等于s的长度最小的连续子数组

    滑动窗口基本思想：
    image.png

    1. class Solution:
    2.     def minSubArrayLen(self, s: int, nums: List[int]) -> int:
    3.         left = 0
    4.         right = 0
    5.         window = []
    6.         min_length = len(nums)
    7.         flag = False
    9.         while right < len(nums):
    10.             window.append(nums[right])
    11.             while sum(window) >= s:
    12.                 flag = True
    13.                 if len(window) <= min_length:
    14.                     min_length = len(window)
    15.                 window.pop(0)
    16.                 left += 1
    17.             right += 1
    19.         return min_length if flag else 0

    基本模板

    1. int left = 0, right = 0;
    3. while (right < s.size()) {
    4.     window.add(s[right]);
    5.     right++;
    7.     while (valid) {
    8.         window.remove(s[left]);
    9.         left++;
    10.     }
    11. }