# C 程序：使用多維數組將兩個矩陣相乘 > 原文： [https://www.programiz.com/c-programming/examples/matrix-multiplication](https://www.programiz.com/c-programming/examples/matrix-multiplication) #### 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) * * * 該程序要求用戶輸入兩個矩陣的大小（行和列）。 為了將兩個矩陣相乘，**第一個矩陣的列數應等于第二個矩陣的行數**。 下面的程序要求兩個矩陣的行數和列數，直到滿足上述條件。 然后，執行兩個矩陣的相乘，結果顯示在屏幕上。 為此，我們創建了三個函數： * `enterData()` - 從用戶那里獲取矩陣元素。 * `multiplyMatrices()` - 將兩個矩陣相乘。 * `display()` - 顯示相乘后的結果矩陣。 * * * ## 通過將矩陣傳遞給函數來相乘 ```c #include <stdio.h> void enterData(int first[][10], int second[][10], int r1, int c1, int r2, int c2); void multiplyMatrices(int first[][10], int second[][10], int multResult[][10], int r1, int c1, int r2, int c2); void display(int mult[][10], int r1, int c2); int main() { int first[10][10], second[10][10], mult[10][10], r1, c1, r2, c2; printf("Enter rows and column for the first matrix: "); scanf("%d %d", &r1, &c1); printf("Enter rows and column for the second matrix: "); scanf("%d %d", &r2, &c2); // Taking input until columns of the first matrix is equal to the rows of the second matrix while (c1 != r2) { printf("Error! Enter rows and columns again.\n"); printf("Enter rows and columns for the first matrix: "); scanf("%d%d", &r1, &c1); printf("Enter rows and columns for the second matrix: "); scanf("%d%d", &r2, &c2); } // Function to take matrices data enterData(first, second, r1, c1, r2, c2); // Function to multiply two matrices. multiplyMatrices(first, second, mult, r1, c1, r2, c2); // Function to display resultant matrix after multiplication. display(mult, r1, c2); return 0; } void enterData(int first[][10], int second[][10], int r1, int c1, int r2, int c2) { printf("\nEnter elements of matrix 1:\n"); for (int i = 0; i < r1; ++i) { for (int j = 0; j < c1; ++j) { printf("Enter a%d%d: ", i + 1, j + 1); scanf("%d", &first[i][j]); } } printf("\nEnter elements of matrix 2:\n"); for (int i = 0; i < r2; ++i) { for (int j = 0; j < c2; ++j) { printf("Enter b%d%d: ", i + 1, j + 1); scanf("%d", &second[i][j]); } } } void multiplyMatrices(int first[][10], int second[][10], int mult[][10], int r1, int c1, int r2, int c2) { // Initializing elements of matrix mult to 0. for (int i = 0; i < r1; ++i) { for (int j = 0; j < c2; ++j) { mult[i][j] = 0; } } // Multiplying first and second matrices and storing in mult. for (int i = 0; i < r1; ++i) { for (int j = 0; j < c2; ++j) { for (int k = 0; k < c1; ++k) { mult[i][j] += first[i][k] * second[k][j]; } } } } void display(int mult[][10], int r1, int c2) { printf("\nOutput Matrix:\n"); for (int i = 0; i < r1; ++i) { for (int j = 0; j < c2; ++j) { printf("%d ", mult[i][j]); if (j == c2 - 1) printf("\n"); } } } ``` **輸出** ```c Enter rows and column for the first matrix: 2 3 Enter rows and column for the second matrix: 3 2 Enter elements of matrix 1: Enter a11: 3 Enter a12: -2 Enter a13: 5 Enter a21: 3 Enter a22: 0 Enter a23: 4 Enter elements of matrix 2: Enter b11: 2 Enter b12: 3 Enter b21: -9 Enter b22: 0 Enter b31: 0 Enter b32: 4 Output Matrix: 24 29 6 25 ```