Answer to Question #293215 in C for Karthi

Question

Let A[nl][ml] and B[n2][m2] be an n x m matrix. Then, find product of C[n] [m], is a A and B is defined as C(i,k) = A(ij) x B(j,k). where j is multipied over for all possible values of i and k.

Input:

2 3

3 2

3 -2 5

3 0 4

2 3

-9 0

0 4

Output:

24 29

6 25

Answer 1

#include <stdio.h>
#include <stdlib.h>


#define N 100


void ReadMatrix(int M[N][N], int n, int m)
{
    int i, j;


    for (i=0; i<n; i++) {
        for (j=0; j<m; j++) {
            scanf("%d", &M[i][j]);
        }
    }
}


void PrintMatrix(int M[N][N], int n, int m)
{
    int i, j;
    for (i=0; i<n; i++) {
        for (j=0; j<m; j++) {
            printf("%3d ", M[i][j]);
        }
        printf("\n");
    }
}


void MultMatrix(int A[N][N], int n1, int m1, 
                int B[N][N], int n2, int m2,
                int C[N][N])
{
    int i, j, k;


    if (m1 != n2) {
        printf("Incorect matixes size");
        exit(1);
    }


    for (i=0; i<n1; i++) {
        for (j=0; j<m2; j++) {
            C[i][j] = 0;
            for (k=0; k<m1; k++) {
                C[i][j] += A[i][k] * B[k][j];
            }
        }
    }
}                


int main() 
{
    int A[N][N], B[N][N], C[N][N];
    int n1, m1, n2, m2;


    scanf("%d %d", &n1, &m1);
    scanf("%d %d", &n2, &m2);
    
    ReadMatrix(A, n1, m1);
    ReadMatrix(B, n2, m2);
    MultMatrix(A, n1, m1, B, n2, m2, C);


    printf("\n");
    PrintMatrix(C, n1, m2);


    return 0;
}