跳转至

344.reverse-string

Statement

Metadata

编写一个函数,其作用是将输入的字符串反转过来。输入字符串以字符数组 s 的形式给出。

不要给另外的数组分配额外的空间,你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。

 

示例 1:

输入:s = ["h","e","l","l","o"]
输出:["o","l","l","e","h"]

示例 2:

输入:s = ["H","a","n","n","a","h"]
输出:["h","a","n","n","a","H"]

 

提示:

  • 1 <= s.length <= 105
  • s[i] 都是 ASCII 码表中的可打印字符

Metadata
  • Link: Reverse String
  • Difficulty: Easy
  • Tag: Recursion Two Pointers String

Write a function that reverses a string. The input string is given as an array of characters s.

You must do this by modifying the input array in-place with O(1) extra memory.

 

Example 1:

Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]

Example 2:

Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]

 

Constraints:

Solution

from typing import List


class Solution:
    def reverseString(self, s: List[str]) -> None:
        """
        Do not return anything, modify s in-place instead.
        """
        n = len(s)
        i = 0
        j = n - 1
        while i < j:
            s[i], s[j] = s[j], s[i]
            i += 1
            j -= 1

最后更新: January 15, 2023
回到页面顶部