Rotate Image.cpp

/* 

    Solution by Rahul Surana
    

    ***********************************************************


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.

        

    ***********************************************************
*/



#include <bits/stdc++.h>
class Solution {
public:
    void rotate(vector<vector<int>>& matrix) {
        int n = matrix.size();
        for(int i = 0; i < ceil(n/2); i++){
            for(int j = i; j < (n-1-i); j++){
                int temp = matrix[i][j];
                matrix[i][j] = matrix[n-1-j][i];
                matrix[n-1-j][i] = matrix[n-1-i][n-1-j];
                matrix[n-1-i][n-1-j] = matrix[j][n-1-i];
                matrix[j][n-1-i] = temp;
            }
        }
    }
};