目录

力扣-反转字符串

目录

🔗 题目链接

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

  • $1 <= s.length <= 10^5$
  • $s[i]$ 都是 ASCII 码表中的可打印字符

库函数,双指针1

迭代

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def reverseString(s: List[str]) -> None:
    if not s:
        return 0
    s[:] = s[::-1]

双指针

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def reverseString(s: list[str]) -> None:
    n = len(s)
    l, r = 0, n-1
    while l < r:
        s[l], s[r] = s[r], s[l]
        l += 1
        r -= 1