Trivial only. Just to use 4 way switch:
class MatrixRotate{ public void rotateMatrix(int[][] matrix){ int MLENGTH = matrix.length; int length = MLENGTH / 2; MLENGTH --; for(int i = 0; i< length; i++){ for( int j = 0; j< length ; j++){ int temp = matrix[i][j]; matrix[i][j] = matrix[j][MLENGTH-i]; matrix[j][MLENGTH -i] = matrix[MLENGTH - i][MLENGTH - j]; matrix[MLENGTH -i][MLENGTH - j] = matrix[MLENGTH - j][i]; matrix[MLENGTH -j][i]= temp; } } } public void printMatrix(int[][] matrix){ for(int i =0; i< matrix.length; i++){ for(int j=0; j<matrix[i].length; j++){ System.out.print(matrix[i][j] + " \t"); } System.out.println(); } } public static void main(String args[]){ int[][] matrix = new int[4][4]; matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3; matrix[0][3] = 4; matrix[1][0] = 5; matrix[1][1] = 6; matrix[1][2] = 7; matrix[1][3] = 8; matrix[2][0] = 9; matrix[2][1] = 10; matrix[2][2] = 11; matrix[2][3] = 12; matrix[3][0] = 13; matrix[3][1] = 14; matrix[3][2] = 15; matrix[3][3] = 16; MatrixRotate rotate = new MatrixRotate(); rotate.printMatrix(matrix); rotate.rotateMatrix(matrix); System.out.println("\n\n"); rotate.printMatrix(matrix); }}