# 矩陣的標量乘法程序 > 原文： [https://www.geeksforgeeks.org/program-for-scalar-multiplication-of-a-matrix/](https://www.geeksforgeeks.org/program-for-scalar-multiplication-of-a-matrix/) 給定一個矩陣和一個標量元素 k，我們的任務是找出該矩陣的標量積。 **示例**： ``` 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 ``` 數為 k（標量）的**標量乘法**，將其乘以矩陣中的每個條目。 矩陣 A 為矩陣 kA。 ## C++ ```cpp // 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 // 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# ```cs // 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 // 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 ``` **輸出**： ``` Scalar Product Matrix is : 4 8 12 16 20 24 28 32 36 ``` * * * * * *