Reverse String

reverseString.js

/**
 * @param {character[]} s
 * @return {void} Do not return anything, modify s in-place instead.
 */
var reverseString = function(s) {
    let start = 0;
    let end = s.length - 1;
    let temp = "";

    while(start <= end) {
        temp = s[start];
        s[start] = s[end];
        s[end] = temp;
        start++;
        end--;
    }
};

// Two pointers and a temp variable approach
// Start poniter points to the start of the array and the end points at the end
// while start <= end swap the characters

// Time: O(n)
// Space: O(1)