344. 反转字符串#

反转字符串-力扣链接

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#

示例 1#

  输入：s = ["h","e","l","l","o"]
  输出：["o","l","l","e","h"]
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示例 2#

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

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

解析#

双指针法#

• 采用双指针法简化时间复杂度。

代码#

  /**
   Do not return anything, modify s in-place instead.
  */
  function reverseString(s: string[]): void {
    let left: number = 0;
    let right: number = s.length - 1;
    while (right > left) {
      swap(s, left, right);
      left++;
      right--;
    }
  }

  function swap(s, a, b) {
    let temp = s[b];
    s[b] = s[a];
    s[a] = temp;
  }
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