Skip to content
Related Articles

Related Articles

Improve Article

Print sum of matrix and its mirror image

  • Difficulty Level : Easy
  • Last Updated : 30 Apr, 2021

You are given a matrix of order N*N. The task is to find the resultant matrix by adding the mirror image of given matrix with the matrix itself.
Examples
 

Input : mat[][] = {{1, 2, 3},
                              {4, 5, 6},
                              {7, 8, 9}}
Output : 4 4 4
               10 10 10
               16 16 16
Explanation:  
Resultant Matrix = {{1, 2, 3},      {{3, 2, 1}, 
                                 {4, 5, 6},   +   {6, 5, 4},
                                 {7, 8, 9}}       {9, 8, 7}}

Input : mat[][] = {{1, 2},
                               {3, 4}}
Output : 3 3
               7 7

 

While finding the mirror image of matrix the row of each element will remain same but the value of its columns will reshuffle. For any element Aij its new position in mirror image will be Ai(n-j). After getting the mirror image of matrix add it to original matrix and print the result.
Points to take care: 
 

  1. Indexing of matrix will start from 0, 0 and ends on n-1, n-1 hence position of any element Aij will be Ai(n-1-j).
  2. While printing the result take care of proper output format

Below is the implementation of the above approach: 
 

C++




// C++ program to find sum of matrix and
// its mirror image
#include <bits/stdc++.h>
 
#define N 4
using namespace std;
 
// Function to print the resultant matrix
void printSum(int mat[][N])
{
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            cout << setw(3) << mat[i][N - 1 - j] + mat[i][j] << " ";
        }
 
        cout << "\n";
    }
}
 
// Driver Code
int main()
{
    int mat[N][N] = { { 2, 4, 6, 8 },
                      { 1, 3, 5, 7 },
                      { 8, 6, 4, 2 },
                      { 7, 5, 3, 1 } };
 
    printSum(mat);
 
    return 0;
}

Java




// Java program to find sum of
// matrix and its mirror image
import java.io.*;
 
class GFG
{
static int N = 4;
 
// Function to print the
// resultant matrix
static void printSum(int mat[][])
{
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            System.out.print((mat[i][N - 1 - j] +
                              mat[i][j]) + " ");
        }
 
        System.out.println();
    }
}
 
// Driver Code
public static void main (String[] args)
{
    int mat[][] = { { 2, 4, 6, 8 },
                    { 1, 3, 5, 7 },
                    { 8, 6, 4, 2 },
                    { 7, 5, 3, 1 } };
 
    printSum(mat);
}
}
 
// This code is contributed by anuj_67

Python3




# Python 3 program to find sum of matrix
# and its mirror image
 
N = 4
 
# Function to print the resultant matrix
def printSum(mat):
    for i in range(N):
        for j in range(N):
            print('{:>3}'.format(mat[i][N - 1 - j] +
                                 mat[i][j]), end =" ")
             
        print("\n", end = "")
 
# Driver Code
if __name__ == '__main__':
    mat = [[2, 4, 6, 8],
           [1, 3, 5, 7],
           [8, 6, 4, 2],
           [7, 5, 3, 1]]
 
    printSum(mat)
 
# This code is contributed by
# Surendra_Gangwar

C#




// C# program to find sum of
// matrix and its mirror image
using System;
 
class GFG
{
static int N = 4;
 
// Function to print the
// resultant matrix
static void printSum(int [,]mat)
{
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            Console.Write((mat[i, N - 1 - j] +
                           mat[i, j]) + " ");
        }
 
        Console.WriteLine();
    }
}
 
// Driver Code
public static void Main ()
{
    int [,]mat = { { 2, 4, 6, 8 },
                   { 1, 3, 5, 7 },
                   { 8, 6, 4, 2 },
                   { 7, 5, 3, 1 } };
 
    printSum(mat);
}
}
 
// This code is contributed by shs..

PHP




<?php
// PHP program to find sum of
// matrix and its mirror image
 
// Function to print the
// resultant matrix
function printSum($mat)
{
    for ($i = 0; $i < 4; $i++)
    {
        for ($j = 0; $j < 4; $j++)
        {
            echo ($mat[$i][4 - 1 - $j] +
                  $mat[$i][$j]) . " " ;
        }
 
        echo "\n";
    }
}
 
// Driver Code
$mat = array(array(2, 4, 6, 8 ),
             array(1, 3, 5, 7),
             array(8, 6, 4, 2),
             array(7, 5, 3, 1));
 
printSum($mat);
     
// This code is contributed
// by Akanksha Rai
?>

Javascript




<script>
 
// Javascript program to find sum of matrix and
// its mirror image
 
var N = 4
 
// Function to print the resultant matrix
function printSum(mat)
{
    for (var i = 0; i < N; i++) {
        for (var j = 0; j < N; j++) {
            document.write( (mat[i][N - 1 - j] + mat[i][j]) + " ");
        }
 
        document.write("<br>");
    }
}
 
// Driver Code
var mat = [ [ 2, 4, 6, 8 ],
                  [ 1, 3, 5, 7 ],
                  [ 8, 6, 4, 2 ],
                  [ 7, 5, 3, 1 ] ];
printSum(mat);
 
</script>
Output: 
10  10  10  10 
  8   8   8   8 
 10  10  10  10 
  8   8   8   8

 

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.




My Personal Notes arrow_drop_up