Understanding Arithmetic Errors in C Programs

[Defennder]

C Program "Arithmetic Error"

I'm writing a C program which prompts a user for an input decimal number (or any integer in base 10) as well as the n-base to which he wishes to convert the number to. However, for some reason my program failed to work and displayed "Arithmetic Error (core dumped", though it compiled successfully (GCC). Here is the website the algorithm I used is based on:

http://www.learn-programming.za.net/articles_decbinhexoct.html

And here is the output I got for a sample input. User input underlined.

Enter decimal number followed by base number: 55 6

No. of digits in final answer is 3

Arithmetic Exception (core dumped)

What does the last line of error mean? The first 2 lines worked perfectly. This is the code:

#include <stdio.h>
#include <math.h>

int main(void)

{

/* Declare and initialise variables */

int y, e, z, m, p, f, g=0, k=2, D=0, n=0, d1, d[9], x[9];



/* Prompt for User Input */

printf("Please enter decimal number followed by base number. \n");



/* Scanf in the values */

scanf("%d %d", &D, &n);



/* Check if entered decimal no. is already in correct base */

y = D/n;





if (y==0)

{ printf("Decimal no. %d has value of %d in base %d \n", D,D,n);

}

/* Digit-by-digit calculation of decimal no. in new base */

else

{ while(y>0)

{ y = D/(pow(n,k));

k+=1;}



printf("No. of digits in final answer is %d \n", k-1);

d1 = D / (pow(n,(k-1)));

e = k-1;

f = k-1;



for (m=2, p=1; m=e, p=e-1; m++, p++)

{ z = pow(n,f);

x[p] = D%z;

f-=1;

d[m] = (x[p])/(pow(n,f));}



printf("Decimal number of %d has value of", D);



g = 1;

while(g<k-1)

{ printf("%d",d[g]);

g += 1; }



printf(" in base %d", n);

}

/* Exit */

return 0;

}

 

[zyh]

I have tested your code in Visual c++, and it reported that
divide by zero...

it's here:
for (m=2, p=1; m=e, p=e-1; m++, p++)
{ z = pow(n,f);
x[p] = D%z;******************************here!
f-=1;
d[m] = (x[p])/(pow(n,f));}
...

it seems that z have the value for each loop: 216->36->6->1->0.
as f becoms -1, the pow(n,-1) return a Zero;

 

[Defennder]

Thanks so much, zyh!