2019-05-19LeetCode344. 反转字符串

双指针，5min

class Solution:
    def reverseString(self, s: List[str]) -> None:
        """
        Do not return anything, modify s in-place instead.
        """
        low,high=0,len(s)-1
        mid=(low+high)//2
        while(low<=mid):
            tmp=s[low]
            s[low]=s[high]
            s[high]=tmp
            low+=1
            high-=1