344. Reverse String

# Easy

如果list长度是偶数，则len(s)/2作为index是中间偏前一位

如果list长度是奇数，则len(s)/2作为index是中间那位

Python

class Solution:
    def reverseString(self, s: List[str]) -> None:
        """
        Do not return anything, modify s in-place instead.
        """
        l = len(s)
        for i in range(l//2):
            tmp = s[i]
            s[i] = s[l-i-1]
            s[l-i-1] = tmp