Example: Matrix Addition using Functions in C

// Matrix Addition using Functions
#include <stdio.h>

// Function to add two matrices and store the result in a third matrix
// Note: For simplicity, matrices are assumed to have a maximum size of 10x10.
// In real-world scenarios, dynamic memory allocation or VLAs might be used.
void addMatrices(int mat1[10][10], int mat2[10][10], int result[10][10], int rows, int cols) {
    // Step 1: Iterate through each row of the matrices
    for (int i = 0; i < rows; i++) {
        // Step 2: Iterate through each column in the current row
        for (int j = 0; j < cols; j++) {
            // Step 3: Add corresponding elements from mat1 and mat2
            // Store the sum in the result matrix at the same position
            result[i][j] = mat1[i][j] + mat2[i][j];
        }
    }
}

// Function to display a matrix
void displayMatrix(int matrix[10][10], int rows, int cols) {
    // Step 1: Print a header for the matrix
    printf("Matrix:\n");
    // Step 2: Iterate through each row to print its elements
    for (int i = 0; i < rows; i++) {
        // Step 3: Iterate through each column to print the element
        for (int j = 0; j < cols; j++) {
            // Print the element followed by a tab for spacing
            printf("%d\t", matrix[i][j]);
        }
        // Move to the next line after printing all elements in a row
        printf("\n");
    }
}

int main() {
    // Step 1: Declare variables for matrix dimensions and the matrices themselves
    int rows, cols;
    int matrix1[10][10], matrix2[10][10], sumMatrix[10][10]; // Assuming max 10x10

    // Step 2: Get dimensions from the user
    printf("Enter number of rows (max 10): ");
    scanf("%d", &rows);
    printf("Enter number of columns (max 10): ");
    scanf("%d", &cols);

    // Basic validation for dimensions
    if (rows <= 0 || rows > 10 || cols <= 0 || cols > 10) {
        printf("Invalid dimensions. Please enter rows/cols between 1 and 10.\n");
        return 1; // Indicate an error
    }

    // Step 3: Get elements of the first matrix from the user
    printf("Enter elements of the first matrix:\n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("Enter element a%d%d: ", i + 1, j + 1);
            scanf("%d", &matrix1[i][j]);
        }
    }

    // Step 4: Get elements of the second matrix from the user
    printf("Enter elements of the second matrix:\n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("Enter element b%d%d: ", i + 1, j + 1);
            scanf("%d", &matrix2[i][j]);
        }
    }

    // Step 5: Display the input matrices for verification
    printf("\n--- Input Matrices ---\n");
    printf("First ");
    displayMatrix(matrix1, rows, cols);
    printf("\nSecond ");
    displayMatrix(matrix2, rows, cols);

    // Step 6: Call the addMatrices function to perform the addition
    addMatrices(matrix1, matrix2, sumMatrix, rows, cols);

    // Step 7: Display the resulting sum matrix
    printf("\n--- Result ---\n");
    printf("Sum of the two matrices:\n");
    displayMatrix(sumMatrix, rows, cols);

    return 0; // Indicate successful execution
}