Rotate_Image.java

// You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).

// 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.

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