Program for scalar multiplication of a matrix

Given a matrix and a scalar element k, our task is to find out the scalar product of that matrix. 

Examples:

Input : mat[][] = {{2, 3}
                   {5, 4}}
        k = 5
Output : 10 15 
         25 20 
We multiply 5 with every element.

Input : 1 2 3 
        4 5 6
        7 8 9
        k = 4
Output :  4 8  12
          16 20 24
          28 32 36 

The scalar multiplication of a number k(scalar), multiply it on every entry in the matrix. and a matrix A is the matrix kA.

C

// C program to find the scalar product
// of a matrix
#include <stdio.h>

// Size of given matrix
#define N 3

void scalarProductMat(int mat[][N], int k)
{
    // scalar element is multiplied by the matrix
    for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++)
            mat[i][j] = mat[i][j] * k;
}

// Driver code
int main()
{
    int mat[N][N] = { { 1, 2, 3 },
                    { 4, 5, 6 },
                    { 7, 8, 9 } };
    int k = 4;

    scalarProductMat(mat, k);

    // to display the resultant matrix
    printf("Scalar Product Matrix is : \n");
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++)
            printf("%d ", mat[i][j]);
        printf("\n");
    }

    return 0;
}

C++

// C++ program to find the scalar product
// of a matrix
#include <bits/stdc++.h>
using namespace std;

// Size of given matrix
#define N 3

void scalarProductMat(int mat[][N], int k)
{
    // scalar element is multiplied by the matrix
    for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++)
            mat[i][j] = mat[i][j] * k;
}

// Driver code
int main()
{
    int mat[N][N]
        = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } };
    int k = 4;

    scalarProductMat(mat, k);

    // to display the resultant matrix
    printf("Scalar Product Matrix is : \n");
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++)
            cout<< mat[i][j]<<" ";
        cout << endl;
    }

    return 0;
}

Java

// Java program to find
// the scalar product
// of a matrix
import java.io.*;

class GFG {

static final int N = 3;
static void scalarProductMat(int mat[][],
                                  int k)
{

    // scalar element is multiplied
    // by the matrix
    for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++)
            mat[i][j] = mat[i][j] * k;
}

// Driver code
public static void main (String[] args)
{
    int mat[][] = { { 1, 2, 3 },
                    { 4, 5, 6 },
                    { 7, 8, 9 } };
    int k = 4;

    scalarProductMat(mat, k);

    // to display the resultant matrix
    System.out.println("Scalar Product Matrix is : ");

    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
            System.out.print(mat[i][j] + " ");
        System.out.println();
    }
}
}

// This code is contributed by Ajit.

Python 3

# Python 3 program to find the scalar
# product of a matrix

# Size of given matrix
N = 3

def scalarProductMat( mat, k):

    # scalar element is multiplied
    # by the matrix
    for i in range( N):
        for j in range( N):
            mat[i][j] = mat[i][j] * k

# Driver code
if __name__ == "__main__":

    mat = [[ 1, 2, 3 ],
           [ 4, 5, 6 ],
           [ 7, 8, 9 ]]
    k = 4

    scalarProductMat(mat, k)

    # to display the resultant matrix
    print("Scalar Product Matrix is : ")
    for i in range(N):
        for j in range(N):
            print(mat[i][j], end = " ")
        print()

# This code is contributed by ita_c

C#

// C# program to find
// the scalar product
// of a matrix
using System;

class GFG{

static int N = 3;
static void scalarProductMat(int[,] mat,
                                  int k)
{

    // scalar element is multiplied
    // by the matrix
    for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++)
            mat[i,j] = mat[i, j] * k;
}

// Driver code
static public void Main ()
{
    int[,] mat = {{1, 2, 3},
                  {4, 5, 6},
                  {7, 8, 9}};
    int k = 4;

    scalarProductMat(mat, k);

    // to display the resultant matrix
    Console.WriteLine("Scalar Product Matrix is : ");

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++)
            Console.Write(mat[i, j] + " ");
        Console.WriteLine();
    }
}
}

// This code is contributed by Ajit.

PHP

<?php
// PHP program to find
// the scalar product
// of a matrix

function scalarProductMat($mat,
                          $k)
{
    $N = 3;

    // scalar element is multiplied
    // by the matrix
    for ( $i = 0; $i < $N; $i++)
        for ($j = 0; $j < $N; $j++)
            $mat[$i][$j] = $mat[$i][$j] * $k;

    return $mat;
}

// Driver code
$N = 3;
$mat = array(array(1, 2, 3 ),
             array( 4, 5, 6 ),
             array(7, 8, 9 ));
$k = 4;

$mat1 = scalarProductMat($mat, $k);

// to display the resultant matrix
echo("Scalar Product Matrix is : " . "\n");

for ($i = 0; $i < $N; $i++)
{
    for ($j = 0; $j < $N; $j++)
        echo($mat1[$i][$j] . " ");
    echo "\n";
}

// This code is contributed
// by Mukul Singh

Javascript

<script>

// Javascript program to find the scalar product
// of a matrix

// Size of given matrix
N = 3

function scalarProductMat(mat, k)
{

    // scalar element is multiplied by the matrix
    for (var i = 0; i < N; i++)
        for (var j = 0; j < N; j++)
            mat[i][j] = mat[i][j] * k;
}

// Driver code
var mat = [ [ 1, 2, 3 ],
                [ 4, 5, 6 ],
                [ 7, 8, 9 ] ];
var k = 4;
scalarProductMat(mat, k);

// to display the resultant matrix
document.write("Scalar Product Matrix is : <br>");
for (var i = 0; i < N; i++)
{
    for (var j = 0; j < N; j++)
        document.write(mat[i][j]+" ");
    document.write("<br>");
}

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

Output:

Scalar Product Matrix is : 
4 8 12 
16 20 24 
28 32 36

Time Complexity: O(n²),

Auxiliary Space: O(1), since no extra space has been taken.