Program to concatenate two given Matrices of same size

Given two matrices A and B of size M x N, the task is to concatenate them into one matrix.
Concatenation of matrix: The process of appending elements of every row of the matrix one after the other is known as the Concatenation of matrix. 
Examples:

Input:
A[][] = {{1, 2}, 
         {3, 4}},
B[][] = {{5, 6}, 
         {7, 8}}
Output: 
1 2 5 6
3 4 7 8
Explanation:
Elements of every row of the matrix B 
is appended into the row of matrix A.

Input: 
A[][] = {{2, 4}, 
         {3, 4}}
B[][] = {{1, 2}, 
         {1, 3}}       
Output: 
2 4 1 2 
3 4 1 3

Approach: The idea is to declare a matrix of size N x 2*M, then traverse over matrix A and store the elements in the first half of the matrix and then similarly iterate over matrix B and store the elements in another half of the matrix with the help of the below formulae: 

// For filling the
// first half of matrix
matrix[i][j] = A[i][j]

// For filling the
// second half of matrix
matrix[i][j+N] = A[i][j + N]

Below is the implementation of the above approach: 

C++

// C++ implementation to concatenate
// two matrices of size N x M

#include <bits/stdc++.h>

using namespace std;

#define M 2
#define N 2

// Function to concatenate two
// matrices A[][] and B[][]
void mergeMatrix(int A[M][N],
                 int B[M][N])
{

    // Matrix to store
    // the result
    int C[M][2 * N];

    // Merge the two matrices
    for (int i = 0; i < M; i++) {
        for (int j = 0; j < N; j++) {

            // To store elements
            // of matrix A
            C[i][j] = A[i][j];

            // To store elements
            // of matrix B
            C[i][j + N] = B[i][j];
        }
    }

    // Print the result
    for (int i = 0; i < M; i++) {
        for (int j = 0; j < 2 * N;
             j++)
            cout << C[i][j] << " ";
        cout << endl;
    }
}

// Driven Code
int main()
{
    int A[M][N] = { { 1, 2 },
                    { 3, 4 } };

    int B[M][N] = { { 5, 6 },
                    { 7, 8 } };

    // Find the merge of
    // the 2 matrices
    mergeMatrix(A, B);

    return 0;
}

Java

// Java implementation to concatenate
// two matrices of size N x M
class GFG{

static final int M = 2;
static final int N = 2;

// Function to concatenate two
// matrices A[][] and B[][]
static void mergeMatrix(int A[][],
                        int B[][])
{

    // Matrix to store
    // the result
    int [][]C = new int[M][2 * N];

    // Merge the two matrices
    for(int i = 0; i < M; i++)
    {
       for(int j = 0; j < N; j++)
       {
          // To store elements
          // of matrix A
          C[i][j] = A[i][j];
          
          // To store elements
          // of matrix B
          C[i][j + N] = B[i][j];
           
       }
    }

    // Print the result
    for(int i = 0; i < M; i++)
    {
       for(int j = 0; j < 2 * N; j++)
          System.out.print(C[i][j] + " ");

       System.out.println();
    }
}

// Driven Code
public static void main(String[] args)
{
    int A[][] = { { 1, 2 },
                  { 3, 4 } };

    int B[][] = { { 5, 6 },
                  { 7, 8 } };

    // Find the merge of
    // the 2 matrices
    mergeMatrix(A, B);
}
}

// This code is contributed by gauravrajput1

Python3

# Python3 implementation to concatenate
# two matrices of size N x M

M = 2
N = 2

# Function to concatenate two
# matrices A[][] and B[][]
def mergeMatrix(A, B):

    # Matrix to store
    # the result
    C = [[0 for j in range(2 * N)] 
            for i in range(M)]
    
    # Merge the two matrices
    for i in range(M):
        for j in range(N):
            
            # To store elements
            # of matrix A
            C[i][j] = A[i][j]
            
            # To store elements
            # of matrix B
            C[i][j + N] = B[i][j]
    
    # Print the result
    for i in range(M):
        for j in range(2 * N):     
            print(C[i][j], end = ' ')
            
        print()

# Driver code 
if __name__=='__main__':
    
    A = [ [1, 2], [3, 4] ]
    B = [ [5, 6], [7, 8] ]
    
    # Find the merge of
    # the 2 matrices
    mergeMatrix(A, B)

# This code is contributed by rutvik_56

C#

// C# implementation to concatenate 
// two matrices of size N x M 
using System;

class GFG{
    
const int M = 2; 
const int N = 2; 
    
// Function to concatenate two 
// matrices A[][] and B[][] 
static void mergeMatrix(int[,] A, int[,] B) 
{ 
    
    // Matrix to store 
    // the result 
    int[,] C = new int[M, 2 * N]; 
    
    // Merge the two matrices 
    for(int i = 0; i < M; i++) 
    { 
       for(int j = 0; j < N; j++)
       { 
           
          // To store elements 
          // of matrix A 
          C[i, j] = A[i, j]; 
          
          // To store elements 
          // of matrix B 
          C[i, j + N] = B[i, j]; 
       } 
    } 
    
    // Print the result 
    for(int i = 0; i < M; i++) 
    { 
       for(int j = 0; j < 2 * N; j++) 
          Console.Write(C[i, j] + " ");
    
       Console.WriteLine();
    } 
} 

// Driver code
static void Main()
{
    int[,] A = { { 1, 2 }, 
                 { 3, 4 } }; 

    int[,] B = { { 5, 6 }, 
                 { 7, 8 } }; 
    
    // Find the merge of 
    // the 2 matrices 
    mergeMatrix(A, B); 
}
}

// This code is contributed by divyeshrabadiya07

JavaScript

<script>
// Javascript implementation to concatenate
// two matrices of size N x M
M = 2
N = 2

// Function to concatenate two
// matrices A[][] and B[][]
function mergeMatrix(A,B)
{

    // Matrix to store
    // the result
    var C = [[0,0,0,0], [0,0,0,0]]

    // Merge the two matrices
    for (var i = 0; i < M; i++) 
    {
        for (var j = 0; j < N; j++)
        {

            // To store elements
            // of matrix A
            C[i][j] = A[i][j];

            // To store elements
            // of matrix B
            C[i][j + N] = B[i][j];
        }
    }

    // Print the result
    for (var i = 0; i < M; i++) 
    {
        for (var j = 0; j < 2 * N;
             j++)
            document.write( C[i][j] + " ");
        document.write("<br>");
    }
}

// Driven Code
var A = [ [ 1, 2 ],
                [ 3, 4 ] ];
var B = [ [ 5, 6 ],
                [ 7, 8 ] ];
                
// Find the merge of
// the 2 matrices
mergeMatrix(A, B);

// This code is contributed by noob2000.
</script>

Output:

1 2 5 6 
3 4 7 8

Time Complexity: O(M * N)

Auxiliary Space: O(M * N), since M * N extra space has been taken.

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