Example: C program to Multiply two Matrices using Multi-dimensional Arrays

// C program to Multiply two Matrices using Multi-dimensional Arrays
#include <stdio.h>

// It's the main function of the program
int main() {
    int rows_1, col_1;
    printf("Enter No. of Row & Column:\n");
    scanf("%d %d", &rows_1, &col_1);

    // Transpose the dimension of the first matrix into the second matrix
    // M1[2 x 3] can multiply with M2[3 x 2]
    int rows_2 = col_1, col_2 = rows_1;

    int matrix_1[rows_1][col_1];
    int matrix_2[rows_2][col_2];
    int matrix_mul[rows_1][rows_1];

    // Step-1 Enter the values of first matrix
    printf("\nEnter the values of the first matrix - [%d x %d]\n", rows_1, col_1);
    for (int i = 0; i < rows_1; i++) {
        for (int j = 0; j < col_1; j++) {
            printf("Enter value - M1[%d][%d]: ", i, j);
            scanf("%d", &matrix_1[i][j]);
        }
    }

    // Step-2 Enter the values of second matrix
    printf("\nEnter the values of the second matrix - [%d x %d]\n", rows_2, col_2);
    for (int i = 0; i < rows_2; i++) {
        for (int j = 0; j < col_2; j++) {
            printf("Enter value - M2[%d][%d]: ", i, j);
            scanf("%d", &matrix_2[i][j]);
        }
    }

    // Step-3 Initialize the multiplication matrix with 0 values
    for (int i = 0; i < rows_1; i++) {
        for (int j = 0; j < rows_2; j++) {
            matrix_mul[i][j] = 0;
        }
    }

    // Step-4 Multiply the matrices M1 & M2 and store these values in another matrices `matrix_mul`
    for (int i = 0; i < rows_1; i++) {
        for (int j = 0; j < col_2; j++) {
            for (int k = 0; k < col_1; k++) {
                matrix_mul[i][j] += matrix_1[i][k] * matrix_2[k][j];
            }
        }
    }

    // Step-5 Final output of the program to print the final matrices
    printf("\nMultiplication of two matrices matrix_1 & matrix_2\n");
    for (int i = 0; i < rows_1; i++) {
        for (int j = 0; j < col_2; j++) {
            printf("%d\t", matrix_mul[i][j]);
        }
        printf("\n");
    }
    return 0;
}