Problem Statement
Write a function that reverses a string. The input string is given as an array of characters char[].
Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
You may assume all the characters consist of printable ascii characters.
Example 1:
Input: ["h","e","l","l","o"] Output: ["o","l","l","e","h"]
Example 2:
Input: ["H","a","n","n","a","h"] Output: ["h","a","n","n","a","H"]
Solution:
class Solution:
def reverseString(self, s: List[str]) -> None:
"""
Do not return anything, modify s in-place instead.
"""
if not s:
return
start=0
end=len(s)-1
while start<end:
s[start], s[end] = s[end], s[start]
start+=1
end-=1
