How do you multiply a matrix by a scalar in python?

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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++

#include

using namespace std;

#define N 3

void scalarProductMat(int mat[][N], int k)

{

    for (int i = 0; i < N; i++)

        for (int j = 0; j < N; j++)

            mat[i][j] = mat[i][j] * k;       

}

int main()

{

    int mat[N][N] = { { 1, 2, 3 },

                      { 4, 5, 6 },

                      { 7, 8, 9 } };

    int k = 4;

    scalarProductMat(mat, k);

    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

import java.io.*;

class GFG {

static final int N = 3;

static void scalarProductMat(int mat[][],

                                  int k)

{

    for (int i = 0; i < N; i++)

        for (int j = 0; j < N; j++)

            mat[i][j] = mat[i][j] * k;

}

public static void main (String[] args)

{

    int mat[][] = { { 1, 2, 3 },

                    { 4, 5, 6 },

                    { 7, 8, 9 } };

    int k = 4;

    scalarProductMat(mat, k);

    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();

    }

}

}

Python 3

N = 3

def scalarProductMat( mat, k):

    for i in range( N):

        for j in range( N):

            mat[i][j] = mat[i][j] * k    

if __name__ == "__main__":

    mat = [[ 1, 2, 3 ],

           [ 4, 5, 6 ],

           [ 7, 8, 9 ]]

    k = 4

    scalarProductMat(mat, k)

    print("Scalar Product Matrix is : ")

    for i in range(N):

        for j in range(N):

            print(mat[i][j], end = " ")

        print()

C#

using System;

class GFG{

static int N = 3;

static void scalarProductMat(int[,] mat,

                                  int k)

{

    for (int i = 0; i < N; i++)

        for (int j = 0; j < N; j++)

            mat[i,j] = mat[i, j] * k;    

}

static public void Main ()

{

    int[,] mat = {{1, 2, 3},

                  {4, 5, 6},

                  {7, 8, 9}};

    int k = 4;

    scalarProductMat(mat, k);

    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();

    }

}

}

PHP

function scalarProductMat($mat,

                          $k)

{

    $N = 3;

    for ( $i = 0; $i < $N; $i++)

        for ($j = 0; $j < $N; $j++)

            $mat[$i][$j] = $mat[$i][$j] * $k;

    return $mat;

}

$N = 3;

$mat = array(array(1, 2, 3 ),

             array( 4, 5, 6 ),

             array(7, 8, 9 ));

$k = 4;

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

echo("Scalar Product Matrix is : " . "\n");

for ($i = 0; $i < $N; $i++)

{

    for ($j = 0; $j < $N; $j++)

        echo($mat1[$i][$j] . " ");

    echo "\n";

}

Javascript

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.