package com.interview.multiarray;

/**
 * Date 07/31/2016
 * @author Tushar Roy
 *
 * You are given an n x n 2D matrix representing an image.
 * Rotate the image by 90 degrees (clockwise).
 *
 * https://leetcode.com/problems/rotate-image/
 */
public class RotateImage {

	public void rotate(int[][] matrix) {
		int length = matrix.length-1;
		int j=0;
		while(j < matrix.length/2){
		
			for(int i=j; i < length-j; i++){
				int temp = matrix[j][i];
				matrix[j][i] = matrix[length-i][j];
				matrix[length-i][j] = matrix[length-j][length-i];
				matrix[length-j][length-i] = matrix[i][length-j];
				matrix[i][length-j] = temp;
			}
			j++;
		}
	}
	
	private void print(int arr[][]){
		for(int i=0; i < arr.length; i++){
			for(int j=0; j < arr.length; j++){
				System.out.print(arr[i][j] + " ");
			}
			System.out.print("\n");
		}
	}
	
	public static void main(String args[]){
		
		int matrix[][] = {{1,2,3,4,20},{5,6,7,8,30},{9,10,11,12,40},{13,14,15,16,50},{21,22,23,24,25}};
		RotateImage ti = new RotateImage();
		ti.rotate(matrix);
		ti.print(matrix);
	}
}

package com.interview.multiarray;

/**
 * Date 07/31/2016
 * @author Tushar Roy
 *
 * You are given an n x n 2D matrix representing an image.
 * Rotate the image by 90 degrees (clockwise).
 *
 * https://leetcode.com/problems/rotate-image/
 */
public class RotateImage {

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

	private void print(int arr[][]){
		for(int i=0; i < arr.length; i++){
			for(int j=0; j < arr.length; j++){
				System.out.print(arr[i][j] + " ");
			}
			System.out.print("\n");
		}
	}

	public static void main(String args[]){

		int matrix[][] = {{1,2,3,4,20},{5,6,7,8,30},{9,10,11,12,40},{13,14,15,16,50},{21,22,23,24,25}};
		RotateImage ti = new RotateImage();
		ti.rotate(matrix);
		ti.print(matrix);
	}
}

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