344-reverse-string.java

class Solution {
    public void reverseString(char[] s) {
        int left = 0;
        int right = s.length - 1;
        while (left < right) {
            char temp = s[left];
            s[left] = s[right];
            s[right] = temp;
            left += 1;
            right -= 1;
        }
        return;
    }
}

// time O(n)
// space O(1)
// using array and two pointers opposite direction and shrink type