#include <stdio.h>
#include <stdlib.h>
 
int main() {
    int **A, **B, **C;
    int r1, c1, r2, c2, i, j, k;
 
    // Step 1: Input dimensions of matrices
    printf("Enter number of rows for Matrix A: ");
    scanf("%d", &r1);
    printf("Enter number of columns for Matrix A: ");
    scanf("%d", &c1);
    printf("Enter number of rows for Matrix B: ");
    scanf("%d", &r2);
    printf("Enter number of columns for Matrix B: ");
    scanf("%d", &c2);
 
    // Step 2: Validate matrix multiplication rule
    if (c1 != r2) {
        printf("\nMatrix multiplication not possible!\n");
        printf("Columns of A must equal rows of B.\n");
        return 1;
    }
 
    // Step 3: Allocate memory dynamically for A, B, and C
    A = (int**) malloc(r1 * sizeof(int*));
    B = (int**) malloc(r2 * sizeof(int*));
    C = (int**) malloc(r1 * sizeof(int*));
 
    if (A == NULL || B == NULL || C == NULL) {
        printf("Memory allocation failed!\n");
        return 1;
    }
 
    for (i = 0; i < r1; i++)
        A[i] = (int*) malloc(c1 * sizeof(int));
    for (i = 0; i < r2; i++)
        B[i] = (int*) malloc(c2 * sizeof(int));
    for (i = 0; i < r1; i++)
        C[i] = (int*) malloc(c2 * sizeof(int));
 
    // Step 4: Input Matrix A
    printf("\nEnter elements of Matrix A:\n");
    for (i = 0; i < r1; i++) {
        for (j = 0; j < c1; j++) {
            printf("A[%d][%d] = ", i, j);
            scanf("%d", &A[i][j]);
        }
    }
 
    // Step 5: Input Matrix B
    printf("\nEnter elements of Matrix B:\n");
    for (i = 0; i < r2; i++) {
        for (j = 0; j < c2; j++) {
            printf("B[%d][%d] = ", i, j);
            scanf("%d", &B[i][j]);
        }
    }
 
    // Step 6: Matrix Multiplication Logic
    for (i = 0; i < r1; i++) {
        for (j = 0; j < c2; j++) {
            C[i][j] = 0;
            for (k = 0; k < c1; k++) {
                C[i][j] += A[i][k] * B[k][j];
            }
        }
    }
 
    // Step 7: Display Resultant Matrix
    printf("\nResultant Matrix (A x B):\n");
    for (i = 0; i < r1; i++) {
        for (j = 0; j < c2; j++) {
            printf("%d\t", C[i][j]);
        }
        printf("\n");
    }
 
    // Step 8: Free dynamically allocated memory
    for (i = 0; i < r1; i++) free(A[i]);
    for (i = 0; i < r2; i++) free(B[i]);
    for (i = 0; i < r1; i++) free(C[i]);
    free(A);
    free(B);
    free(C);
 
    return 0;
}