I'm so confused...

Alright, i'm going to try to explain this assingment the best that i can... we have to write a program that will scan in #'s of large integers into a link list and then make it so the user can add or subtract those numbers with another set of numbers in a link list... I'm gettin errors in the addition when it adds for some reason it isn't adding correctly.. the last number it prints twice.. and if one # is 1234 and the other is 12 it will give me 46 only the last 2 numbers will be added... i tried adding leading zeros a while ago to fix that error but it never worked out correctly... there are flaws all throughout this program and i was going to do it without asking for help but it's due in a day and i have no clue how to fix it. Any help that you can provide would be great. Thanks -John

here is the integer.h file...

Code:

typedef struct integerNode{
      int integer;
 struct integerNode *next;
   };
typedef struct integerNode1{
	  int integer1;
      struct integerNode1 *next;
   };
typedef struct integerNode2{
		int integer2;
		struct integerNode2 *next;
   };

int AddTwoIntegers(int, int);
int ReadInt();
void PrintInteger(int);
int compare(int, int);
int SubtractIntegers(int, int);
int RecycleInteger(int);

Here's the main program's code...

Code:

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include "integer.h"

#ifndef _bigint_h
#define _bigint_h

int x;
int n1;
int n2;
int n;
int cnt;
int cnt1;
int cnt2;
int myint;
int sum;
int rollover;
int flag;
int result;
int temp;

	struct integerNode *head = NULL;
	struct integerNode *curr;
	struct integerNode1 *head1 = NULL;
	struct integerNode1 *curr1;
	struct integerNode2 *head2 = NULL;
	struct integerNode2 *curr2;

void main()
	{
		printf("\n\n1. Add\n2. Subtraction\n3. Quit\n\nEnter Choice: ");
		scanf("%d", &x);
		switch(x){
		case 1:
			myint = ReadInt();
			cnt = 0;
			for(x=0;x < myint; x++){
			n1 = curr -> integer;
			n2 = curr1 -> integer1;
			result = AddTwoIntegers(n1, n2);
			}
			n = result;
			PrintInteger(n);			
			(int)head = RecycleInteger((int)head);
			main();
		case 2:
			myint = ReadInt();
			for(x=0;x < myint; x++){
			n1 = curr -> integer;
			n2 = curr1 -> integer1;
			flag = compare(n1, n2);
			temp=flag+temp;
			}
			if (temp<0){
			for(x=0;x < myint; x++){
			n1 = curr -> integer;
			n2 = curr1 -> integer1;
			result = SubtractIntegers(n2, n1);
			}}
			else {
			for(x=0;x < myint; x++){
			n1 = curr -> integer;
			n2 = curr1 -> integer1;
			result = SubtractIntegers(n1, n2);
			}
			PrintInteger(n);
			(int)head = RecycleInteger((int)head);
			main();
		case 3:
			exit (0);
		default:
			exit (0);
		}
	}
}

	int ReadInt()
		{
		cnt1=0;
		while(myint = getchar()){
		if (isdigit(myint) == 0){break;}}
        
		printf("Enter the first number: ");
		 while(myint = getchar()){
		 if (isdigit(myint) == 0){break;}
		 curr = malloc(sizeof(struct integerNode));
         curr -> integer = myint-48;
         curr -> next = head;
         head = curr;
		 cnt1++;
		 }
		
		 cnt2=0;
		 printf("Enter the second number: ");
	     while(myint = getchar()){
		 if (isdigit(myint) == 0){break;}
		 curr1 = malloc(sizeof(struct integerNode1));
         curr1 -> integer1 = myint-48;
         curr1 -> next = head1;
         head1 = curr1;
		 cnt2++;
				}
		 if(cnt1<cnt2){return cnt1;}
		 if(cnt2<cnt1){return cnt2;}
		else return cnt1;
		}


	int AddTwoIntegers(n1, n2)
		{			
			n1 = n1 + rollover;
			sum = n1 + n2;
			rollover = 0;
			if (sum>9){sum = sum - 10; rollover = 1;}	
			curr2 = malloc(sizeof(struct integerNode2));
			curr2 -> integer2 = sum;
			curr2 -> next = head2;
			head2 = curr2;
			cnt2++;
       		curr1 = head1;
			head1 = head1 -> next;
			curr = head;
			head = head -> next;

		return cnt2;
		}
	
	void PrintInteger(n)
		{
		int i;
		for(i=0;i<n-3;i++){
			printf("%d", curr2->integer2);
			curr2 = curr2 -> next;
						}
		}
	
	int compare(n1, n2)
		{
		if(n1==n2){return 0;}
		if(n1>n2){return 1;}
		if(n2>n1){return -1;}
		return 0;
		}
	
	int SubtractIntegers(n1, n2)
		{
			sum = n1 - n2;
			curr2 = malloc(sizeof(struct integerNode2));
			curr2 -> integer2 = sum;
			curr2 -> next = head2;
			head2 = curr2;
			cnt2++;
			curr1 = head1;
			head1 = head1 -> next;
			curr = head;
			head = head -> next;
		return 0;
		}
	
	int RecycleInteger(n)
		{
		while(head != NULL)
		{         
		RecycleInteger((int)head->next);
		free(head);       
		}
		return 0;
		}
#endif

Just one quick comment, the function main() should not be recursed i.e.

main(){ main(){ main()...etc.} }

Recursion is valid solution but not in this case and defiantly not with main().

try the following structure, this will not fix your posted problem:

Code:

int main()
{
      bool bQuit = FALSE; 
      do
      {
            printf("\n\n1. Add\n2. Subtraction\n3. Quit\n\nEnter Choice: ");
            scanf("%d", &x);
            switch(x)
            {
                  case 1: 
                       break;
                  case 2:	
                       break;
                  case 3:
                  default:
                       bQuit = TRUE; 
                       break;
            }
      }while( bQuit != TRUE );
       return 0;	
}