0.3 滑动窗口

[209. 长度最小的子数组](https://leetcode.cn/problems/minimum-size-subarray-sum/description/?envType=study-plan-v2&envId=top-interview-150)
```python
class Solution:
    def minSubArrayLen(self, target: int, nums: List[int]) -> int:
        n = len(nums)
        left = right = 0
        res = n + 1
        total = 0
        while right < n:
            total += nums[right]
            while total >= target:
                res = min(res, right - left + 1)
                total -= nums[left]
                left += 1
            right += 1
        return res if res != n + 1 else 0
```
[3. 无重复字符的最长子串](https://leetcode.cn/problems/longest-substring-without-repeating-characters/description/?envType=study-plan-v2&envId=top-interview-150)
```python
class Solution:
    def lengthOfLongestSubstring(self, s: str) -> int:
        st = set()
        res = 0
        left = 0
        for right, c in enumerate(s):
            while c in st:
                st.remove(s[left])
                left += 1
            st.add(s[right])
            res = max(res, right - left + 1)
        return res
```
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```python

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```python

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