mport java.util.Scanner;public class InterviewBit{ public static void main(String[] args) { Scanner sc = new Scanner(System.in); int no; System.out.print("Enter size of Array : "); no = sc.nextInt(); int[][] a = new int[no][no]; System.out.print("Enter "+ no*no+" Element Array : "); for(int i = 0; i<no; i++){ for(int j = 0; j<no; j++){ a[i][j] = sc.nextInt(); } } System.out.print("\nArray Before Rotation\N\n"); for(int i = 0; i<no; i++){ for(int j = 0; j<no; j++){ System.out.print(a[i][j] + " "); } System.out.println(); } System.out.println("\n"); //Rotation //Transpose for(int i = 0; i < no; i++){ for(int j = i; j < no; j++){ int temp = a[i][j]; a[i][j] = a[j][i]; a[j][i] = temp; } } //Reverse Each row for(int i = 0; i < no; i++){ int l, j; for(j = 0, l = no -1; j < l; j++){ int temp = a[i][j]; a[i][j] = a[i][l]; a[i][l] = temp; l--; } } System.out.println("Array After Rotation - \n"); for(int i = 0; i<no; i++){ for(int j = 0; j<no; j++){ System.out.print(a[i][j] + " "); } System.out.println(); } }}

In the above code, for rotating the MATRIX to  90 degrees we are first TRANSPOSING the matrix so the row BECOMES the column. And after that, we are reversing each row in the matrix. So this is how the matrix GOT rotated.