public class Solution { public void rotate(int[][] matrix) { int n = matrix.length; int count = (n + 1) / 2; for (int i = 0; i < count; i++) { for (int j = i; j < n - i - 1; j++) { int tmp1 = matrix[i][j]; int tmp2 = matrix[j][n - 1 - i]; int tmp3 = matrix[n - 1 - i][n - 1 - j]; int tmp4 = matrix[n - 1 - j][i]; matrix[i][j] = tmp4; matrix[j][n - 1 - i] = tmp1; matrix[n - 1 - i][n - 1 - j] = tmp2; matrix[n - 1 - j][i] = tmp3; } } } }