C++: Turn a matrix by 180 degree.

We are given a matrix of any dimension and we need to turn it by 180 degree. Here is the source code for the algorithm in c++.

	#include <bits/stdc++.h>
	using namespace std;
	#define R 3
	#define C 4
	void printMatrix(int mat[][S]);
	void turnOneEighty(int mat[R][C]) {
	int row = 0, m = R-1;
	while(row < m) {
	for(int i=0; i < C; i++)
	swap(mat[row][i], mat[m][C-1-i]);
	row++;
	m--;
	if(row == m) {
	int col = 0, n = C-1;
	while(col < n)
	swap(mat[row][col++], mat[row][n--]);
	}
	}
	cout<<"\n\nMatrix turned 180 degree "<<endl;
	printMatrix(mat);
	}
	int main() {
	int mat[R][C] = { {1, 2, 3, 4},
	{5, 6, 7, 8},
	{9, 10, 11, 12} };
	cout<<"\nOriginal matrix is "<<endl;
	printMatrix(mat);
	turnOneEighty(mat);
	return 0;
	}

view raw turn_one_eighty.cpp hosted with ❤ by GitHub

Output:  12  11  10  9
               8    7    6   5
               4    3    2    1