Rotate Image

class Solution {
    public void rotate(int[][] mat) {
        int n = mat.length;

        // transpose 
        for(int i=0; i<n; i++) {
            for(int j=0; j<i; j++) {
                int temp = mat[i][j];
                mat[i][j] = mat[j][i];
                mat[j][i] = temp;
            }
        }
        // row reverse
        for(int i=0; i<n; i++) {
            int j = 0, k = n-1;
            while(j<k) {
                int temp = mat[i][j];
                mat[i][j] = mat[i][k];
                mat[i][k] = temp;
                j++; k--;
            }
        }
    }
}