C :: Program Seems To Be Crashing At Random Numbers

When I go to run the Fibonacci function ( fib ), it begins to return incorrect calculations towards the higher numbers, but then seems to correct itself for a little bit, but then does it again and ultimately crashes. And the program seems to be crashing at random numbers. Sometimes the it will make it up to F(55), other times it will only get to F(20).

Also, when I go to run the program on a Linux server, it segfaults, but it doesn't when I just run it on my IDE. the function adds two arrays with individual digits together. It does this to allow the program to add numbers that would exceed the boundaries of INT_MAX.

Here is the header file "Fibonacci.h":

Code:

#ifndef __FIBONACCI_H
#define __FIBONACCI_H
typedef struct HugeInteger
{
// a dynamically allocated array to hold the digits of a huge integer
int *digits;
// the number of digits in the huge integer (approx. equal to array length)
int length;
} HugeInteger;
}

[code]....