Example: Matrix Multiplication with Compatibility Check in C

// Matrix Multiplication with Compatibility Check
#include <stdio.h>

#define MAX_DIM 10 // Define a maximum dimension for matrices

// Function to read matrix elements
void readMatrix(int matrix[MAX_DIM][MAX_DIM], int rows, int cols) {
    printf("Enter elements:\n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("Enter element [%d][%d]: ", i, j);
            scanf("%d", &matrix[i][j]);
        }
    }
}

// Function to print matrix elements
void printMatrix(int matrix[MAX_DIM][MAX_DIM], int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d\t", matrix[i][j]);
        }
        printf("\n");
    }
}

int main() {
    int mat1[MAX_DIM][MAX_DIM], mat2[MAX_DIM][MAX_DIM], result[MAX_DIM][MAX_DIM];
    int r1, c1, r2, c2;

    // Step 1: Get dimensions for the first matrix
    printf("Enter rows and columns for first matrix (e.g., 2 3): ");
    scanf("%d %d", &r1, &c1);

    // Step 2: Get dimensions for the second matrix
    printf("Enter rows and columns for second matrix (e.g., 3 2): ");
    scanf("%d %d", &r2, &c2);

    // Step 3: Check compatibility for multiplication
    if (c1 != r2) {
        printf("Error: Matrices are not compatible for multiplication.\n");
        printf("Number of columns in first matrix must be equal to number of rows in second matrix.\n");
        return 1; // Indicate an error
    }

    // Step 4: Read elements for the first matrix
    printf("\n--- Enter elements for First Matrix (%dx%d) ---\n", r1, c1);
    readMatrix(mat1, r1, c1);

    // Step 5: Read elements for the second matrix
    printf("\n--- Enter elements for Second Matrix (%dx%d) ---\n", r2, c2);
    readMatrix(mat2, r2, c2);

    // Step 6: Perform matrix multiplication
    // The resulting matrix will have dimensions r1 x c2
    for (int i = 0; i < r1; i++) {
        for (int j = 0; j < c2; j++) {
            result[i][j] = 0; // Initialize element to 0
            for (int k = 0; k < c1; k++) { // Or k < r2, since c1 == r2
                result[i][j] += mat1[i][k] * mat2[k][j];
            }
        }
    }

    // Step 7: Display the matrices and their product
    printf("\n--- First Matrix ---\n");
    printMatrix(mat1, r1, c1);

    printf("\n--- Second Matrix ---\n");
    printMatrix(mat2, r2, c2);

    printf("\n--- Product of Matrices (%dx%d) ---\n", r1, c2);
    printMatrix(result, r1, c2);

    return 0; // Indicate successful execution
}