rotateImage.java

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

// Rotate the image by 90 degrees (clockwise).

// Follow up:
    // Could you do this in-place?

public class Solution {

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

}