RotateImage.java

/*You are given an n x n 2D matrix representing an image.

Rotate the image by 90 degrees (clockwise).

Note:

You have to rotate the image in-place, which means you have to modify the input 2D matrix directly.

DO NOT allocate another 2D matrix and do the rotation.

Input format
First line contains one integer N.

Next N line contains N space separated integers

Output format
Print the NxN rotated matrix.

Sample Input 1
3
1 2 3
4 5 6
7 8 9

Sample Output 1
7 4 1
8 5 2
9 6 3

Sample Input 2
4

5 1 9 11
2 4 8 10
13 3 6 7
15 14 12 16

Sample Output 2
15 13 2 5
14 3 4 1
12 6 8 9
16 7 10 11

Constraints
1 <= n <= 100
*/

import java.io.*;
import java.util.*;

public class RotateImage {
    public void rotateImage(int[][] matrix) {
    }

    public static void main(String[] args) throws IOException {
        Scanner scanner = new Scanner(System.in);
        int matrixSize = scanner.nextInt();
        int[][] matrix = new int[matrixSize][matrixSize];
        for (int i = 0; i < matrixSize; ++i) {
            for (int j = 0; j < matrixSize; ++j) {
                matrix[i][j] = scanner.nextInt();
            }
        }
        scanner.close();

        new RotateImage().rotateImage(matrix);
        for (int i = 0; i < matrixSize; ++i) {
            for (int j = i; j < matrixSize; ++j) {
                    int temp = matrix[i][j];
                    matrix[i][j] = matrix[j][i];
                    matrix[j][i] = temp;
                }

            }


            for (int i = 0; i < matrixSize; ++i) {
            for (int j = 0; j < matrixSize/2; ++j) {

                if(i>=0 ) {
                    int temp = matrix[i][j];
                    matrix[i][j] = matrix[i][matrixSize-1-j];
                    matrix[i][matrixSize-1-j] = temp;                
                    }
                }

            }


        
            for (int i = 0; i < matrixSize; ++i) {
            for (int j = 0; j < matrixSize; ++j) {
                System.out.print(matrix[i][j] + " ");
            }
            System.out.println();
        }
        }



        
    }