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Program for scalar multiplication of a matrix

  • Difficulty Level : Basic
  • Last Updated : 19 Apr, 2021

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 

 

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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 <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++)
            printf("%d ", mat[i][j]);
        printf("\n");
    }
 
    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

 




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