Matrix Multiplication in C program

// Matrix Multiplication

#include<stdio.h>

int main() {

int r1, c1, r2, c2, i, j, k;

printf("Enter number of rows for first matrix: ");

scanf("%d", &r1);

printf("Enter number of columns for first matrix: "); scanf("%d", &c1);

printf("Enter number of rows for second matrix: "); scanf("%d", &r2);

printf("Enter number of columns for second matrix: "); scanf("%d", &c2);

if (c1 != r2) { printf("Matrix multiplication not possible!\n"); return 1; }

printf("Enter elements of first matrix:\n");

int mat1[r1][c1], mat2[r2][c2];

for(i = 0; i < r1; i++) {

for(j = 0; j < c1; j++) {

scanf("%d", &mat1[i][j]);

}

}

printf("Enter elements of second matrix:\n");

for(i = 0; i < r2; i++) {

for(j = 0; j < c2; j++) {

scanf("%d", &mat2[i][j]);

}

}

printf("First Matrix:\n");

for(i = 0; i < r1; i++) {

for(j = 0; j < c1; j++) {

printf("%d\t", mat1[i][j]);

}

printf("\n");

}

printf("Second Matrix:\n");

for(i = 0; i < r2; i++) {

for(j = 0; j < c2; j++) {

printf("%d\t", mat2[i][j]);

} printf("\n");

}

int res[r1][c2];

printf("Result Matrix:\n");

for(i = 0; i < r1; i++) {

for(j = 0; j < c2; j++) {

res[i][j] = 0;

for(k = 0; k < c1; k++) {

res[i][j] = res[i][j] + mat1[i][k] * mat2[k][j];

}

printf("%d\t", res[i][j]);

}

printf("\n");

}

return 0;

}

Enter number of rows for first matrix: 2

Enter number of columns for first matrix: 2

Enter number of rows for second matrix: 2

Enter number of columns for second matrix: 2

Enter elements of first matrix:

1 2

1 2

Enter elements of second matrix:

1 2

1 2

First Matrix:

1 2

1 2

Second Matrix:

1 2

1 2

Result Matrix:

3 6

3 6