Rotate Matrix By 90 Degree problem LeetCode

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.


Example 1: 

Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [[7,4,1],[8,5,2],[9,6,3]]


Input: matrix = [[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]
Output: [[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]



Solution :


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

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