BIG WEIRD ANSWER in a MATRIX multiplication program - multiplication

Question

this is a program to multiply 2 matrixes which comes in maths, but dont know why, am getting answers like "-1282230" or some weird numbers. I would like to know what is causing it and how could i fix it? THANK YOU!
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
int main()
{
int m[3][3],m2[3][3],i,je,k,ans[3][3],sum;
// taking inputs from the user for matrix1
printf("Enter the numbers for first matrix");
je=0;
for(i=0;i<3;i++){
printf(" for row %d\n",i+1);
for(je=0;je<3;je++){
scanf("%d",&m[i][je]);
}
}
// taking inputs from the user for matrix2
printf("Enter the numbers for second matrix");
je=0;
for(i=0;i<3;i++){
printf(" for row = %d\n",i+1);
for(je=0;je<3;je++){
scanf("%d",&m2[i][je]);
}
}
// multiplication OR MATRIX CMS HERE;
sum = 0;
for(k=0;k<9;k++){
for(i=0;i<3;i++){
for(je=0;je<3;je++){
sum = m[k][je] * m2[je][i];
ans[i][je] = sum;
}
}
k++;
}
// it ENDS;
puts("ANSWER IS:: \n");
// Displaying answer, matrix;
for(i=0;i<3;i++){
for(je=0;je<3;je++){
printf("%d\t",ans[i][je]);
}
printf("\n");
}
return 0;
}

Answer 1

Here's a working solution. One of the problem with your code is that you aren't setting the sum to 0 after each multiplication.
#include <stdio.h>
int main() {
int m, n, p, q, c, d, k, sum = 0; int first[10][10], second[10][10], multiply[10][10];
printf("Enter number of rows and columns of first matrix\n"); scanf("%d%d", &m, &n); printf("Enter elements of first matrix\n");
for (c = 0; c < m; c++)
for (d = 0; d < n; d++)
scanf("%d", &first[c][d]);
printf("Enter number of rows and columns of second matrix\n"); scanf("%d%d", &p, &q);
if (n != p)
printf("The matrices can't be multiplied with each other.\n"); else {
printf("Enter elements of second matrix\n");
for (c = 0; c < p; c++)
for (d = 0; d < q; d++)
scanf("%d", &second[c][d]);
for (c = 0; c < m; c++) {
for (d = 0; d < q; d++) {
for (k = 0; k < p; k++) {
sum = sum + first[c][k]*second[k][d];
}
multiply[c][d] = sum;
sum = 0;
}
}
printf("Product of the matrices:\n");
for (c = 0; c < m; c++) {
for (d = 0; d < q; d++)
printf("%d\t", multiply[c][d]);
printf("\n");
}
}
return 0; }