Rotate Image.java

class Solution {
  public void rotate(int[][] mat) {
    for (int i = 0; i < mat.length; i++) {
      for (int j = i+1; j < mat[0].length; j++) {
        int temp = mat[i][j];
        mat[i][j] = mat[j][i];
        mat[j][i] = temp;
      }
    }
    for (int i = 0; i < mat.length; i++) {
      for (int j = 0; j < mat[0].length / 2; j++) {
        int temp = mat[i][j];
        mat[i][j] = mat[i][mat.length - j - 1];
        mat[i][mat.length - j - 1] = temp;
      }
    }
  }
}