344. Reverse String #

Problem Statement: #

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: #

• 1 <= s.length <= 10⁵
• s[i] is a printable ascii character.

Solution: #

public void reverseString(char[] s) {
  for (int left = 0, right = s.length - 1; left < right; left++, right--)
    swap(s, left, right);
}

private void swap(char[] s, int a, int b) {
  char temp = s[a];
  s[a] = s[b];
  s[b] = temp;
}

... #