Please Help Me! Executing Problem

[hattourie]

I already compile my C and it went well. But when it comes to execute it, it indicate error,..please help me with this,..

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


struct ptr
{int data;
struct ptr *nextptr;
};


typedef struct ptr POINT;

void printList (POINT *sptr);
insert (POINT **startptr);
deduct (POINT **startptr);

void main()

{
	int choice;
	POINT *startptr=NULL;

	printf("Please key in your choice\n\n");
	printf("1.INSERT\n");
	printf("2.DEDUCT\n");
	printf("3.DISPLAY SCREEN\n");
	printf("4.EXIT\n");
	printf("INPUT : ");
	scanf("%d",&choice);
	

	while (choice!=4)
	{

		if (choice==1)
		{
			insert(&startptr);
		}
		else if (choice==2)
		{
			deduct(&startptr);
		}
		else if (choice==3)
		{
			printList(startptr);
		}

		printf("Please key in your choice\n\n");
	printf("1.INSERT\n");
	printf("2.DEDUCT\n");
	printf("3.DISPLAY SCREEN\n");
	printf("4.EXIT\n");
	printf("INPUT : ");
	scanf("%d",&choice);
	
	}

}

insert(POINT **startptr)
{
	int user_input;
	char user_input2;

	POINT *tptr=NULL, *nextptr=NULL, *lastptr=NULL, *newptr=NULL, *tempptr=NULL;
	
	tptr = *startptr;

	printf("Enter Input : ");
	scanf("%d",&user_input);
	
	while(user_input!=-1)
	{
		if (tptr==NULL)
		{
			tptr=(POINT *) malloc(sizeof(POINT));
			tptr->data=user_input;
			tptr->nextptr=NULL;
			lastptr=tptr;
			*startptr=tptr;
		}

		else
		{
			lastptr->nextptr = (POINT *) malloc(sizeof(POINT));
			lastptr=lastptr->nextptr;
			lastptr->data=user_input;
			lastptr->nextptr=NULL;
		}
		
		printf("Do you want to enter another number? ");
		scanf("%c",&user_input2);

		if (user_input2=='Y'||user_input2=='y')
		{
			printf("Please enter value: ");
			scanf("%d",&user_input);
		}
		else if (user_input=='N'||user_input2=='n')
		{
			user_input=-1;
		}
	}

	return (0);
}

void printList(POINT *sptr)
{
	POINT *tempptr=sptr;

	while (tempptr!=NULL)
		{

		printf("Thank You.\n");
		}

	printf("NULL\n\n");

}

[matsp]

So tell us what the error is, and when the error happens - does it happen immediately, or do you do something to make it happen?

void printList(POINT *sptr)
{
	POINT *tempptr=sptr;

	while (tempptr!=NULL)
		{

		printf("Thank You.\n");
		}

	printf("NULL\n\n");

}

This function will loop forever printing "Thank You." if sptr is not NULL, as there is no changing of tempptr inside the loop.

tptr=(POINT *) malloc(sizeof(POINT));

If you compile this with a C compiler, then it shouldn't need a cast for malloc().

Also, why don't you start your while loop in main ABOVE the menu, rather than duplicating the menu inside the loop.

These two chunks do almost the same thing

			tptr=(POINT *) malloc(sizeof(POINT));
			tptr->data=user_input;
			tptr->nextptr=NULL;
			lastptr=tptr;

and

			lastptr->nextptr = (POINT *) malloc(sizeof(POINT));
			lastptr=lastptr->nextptr;
			lastptr->data=user_input;
			lastptr->nextptr=NULL;

It could be coded differently, using tptr, such that you don't repeat almost identical code. Repeating almost identical code is bad practice, and can lead to subtle problems when you modify one but not the other variant of the almost identical code.
The variables nextptr and newptr aren't used in that function.

--
Mats