344. Reverse String

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

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 <= 10^5
• s[i] is a printable ascii character.

Approach

Solution

/**
 * @param {character[]} s
 * @return {void} Do not return anything, modify s in-place instead.
 */
var reverseString = function(s) {
    let i = 0;
    let j = s.length - 1;
    
    while (i < j) {
        [s[i], s[j]] = [s[j], s[i]];
        j--;
        i++;
    }   
};

Explanation