# C 程序：通過將矩陣傳遞給函數來將兩個矩陣相乘 > 原文： [https://www.programiz.com/c-programming/examples/matrix-multiplication-function](https://www.programiz.com/c-programming/examples/matrix-multiplication-function) #### 在此示例中，您將學習將兩個矩陣相乘并使用用戶定義的函數進行顯示。 要理解此示例，您應該了解以下 [C 編程](/c-programming "C tutorial")主題： * [C 數組](/c-programming/c-arrays) * [C 多維數組](/c-programming/c-multi-dimensional-arrays) * [將數組傳遞給 C 中的函數](/c-programming/c-arrays-functions) * * * 該程序要求用戶輸入矩陣的大小（行和列）。 然后，它要求用戶輸入這些矩陣的元素，最后添加并顯示結果。 要執行此任務，需要執行三個函數： 1. `enterData()`從用戶獲取矩陣元素 2. `multiplyMatrices()`將兩個矩陣相乘 3. `display()`在乘法后顯示結果矩陣 ### 示例：通過將矩陣傳遞給函數來相乘 ```c #include <stdio.h> void enterData(int firstMatrix[][10], int secondMatrix[][10], int rowFirst, int columnFirst, int rowSecond, int columnSecond); void multiplyMatrices(int firstMatrix[][10], int secondMatrix[][10], int multResult[][10], int rowFirst, int columnFirst, int rowSecond, int columnSecond); void display(int mult[][10], int rowFirst, int columnSecond); int main() { int firstMatrix[10][10], secondMatrix[10][10], mult[10][10], rowFirst, columnFirst, rowSecond, columnSecond, i, j, k; printf("Enter rows and column for first matrix: "); scanf("%d %d", &rowFirst, &columnFirst); printf("Enter rows and column for second matrix: "); scanf("%d %d", &rowSecond, &columnSecond); // If colum of first matrix in not equal to row of second matrix, asking user to enter the size of matrix again. while (columnFirst != rowSecond) { printf("Error! column of first matrix not equal to row of second.\n"); printf("Enter rows and column for first matrix: "); scanf("%d%d", &rowFirst, &columnFirst); printf("Enter rows and column for second matrix: "); scanf("%d%d", &rowSecond, &columnSecond); } // Function to take matrices data enterData(firstMatrix, secondMatrix, rowFirst, columnFirst, rowSecond, columnSecond); // Function to multiply two matrices. multiplyMatrices(firstMatrix, secondMatrix, mult, rowFirst, columnFirst, rowSecond, columnSecond); // Function to display resultant matrix after multiplication. display(mult, rowFirst, columnSecond); return 0; } void enterData(int firstMatrix[][10], int secondMatrix[][10], int rowFirst, int columnFirst, int rowSecond, int columnSecond) { int i, j; printf("\nEnter elements of matrix 1:\n"); for(i = 0; i < rowFirst; ++i) { for(j = 0; j < columnFirst; ++j) { printf("Enter elements a%d%d: ", i + 1, j + 1); scanf("%d", &firstMatrix[i][j]); } } printf("\nEnter elements of matrix 2:\n"); for(i = 0; i < rowSecond; ++i) { for(j = 0; j < columnSecond; ++j) { printf("Enter elements b%d%d: ", i + 1, j + 1); scanf("%d", &secondMatrix[i][j]); } } } void multiplyMatrices(int firstMatrix[][10], int secondMatrix[][10], int mult[][10], int rowFirst, int columnFirst, int rowSecond, int columnSecond) { int i, j, k; // Initializing elements of matrix mult to 0. for(i = 0; i < rowFirst; ++i) { for(j = 0; j < columnSecond; ++j) { mult[i][j] = 0; } } // Multiplying matrix firstMatrix and secondMatrix and storing in array mult. for(i = 0; i < rowFirst; ++i) { for(j = 0; j < columnSecond; ++j) { for(k=0; k<columnFirst; ++k) { mult[i][j] += firstMatrix[i][k] * secondMatrix[k][j]; } } } } void display(int mult[][10], int rowFirst, int columnSecond) { int i, j; printf("\nOutput Matrix:\n"); for(i = 0; i < rowFirst; ++i) { for(j = 0; j < columnSecond; ++j) { printf("%d ", mult[i][j]); if(j == columnSecond - 1) printf("\n\n"); } } } ``` **輸出** ```c Enter rows and column for first matrix: 3 2 Enter rows and column for second matrix: 3 2 Error! column of first matrix not equal to row of second. Enter rows and column for first matrix: 2 3 Enter rows and column for second matrix: 3 2 Enter elements of matrix 1: Enter elements a11: 3 Enter elements a12: -2 Enter elements a13: 5 Enter elements a21: 3 Enter elements a22: 0 Enter elements a23: 4 Enter elements of matrix 2: Enter elements b11: 2 Enter elements b12: 3 Enter elements b21: -9 Enter elements b22: 0 Enter elements b31: 0 Enter elements b32: 4 Output Matrix: 24 29 6 25 ```