Thread: inserting into a linked list

I have taken a data structures class which focused primarily on implementing in java but I am trying to apply my knowledge by implementing a few structures in a different language.

currently I am trying to implement a linked list. I have managed to get it working fine so far, but am having trouble with the insert function. I can only insert at the top of the list, after the header. To insert after any given node I must set my current node to current->next after the insertion is completed. How can I accomplish this within the function itself? Thanks for your help. I've posted my code below.

Code:

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

void printList(struct node* list);
int isEmpty(struct node* list);
void makeEmpty(struct node* list);
struct node* find(struct node* list, int item);
void insert(struct node* p, int item);
void removeNode(struct node *list, int item);

struct node
{
	int data;
	struct node* next;
};


int main()
{
	struct node *root;
	struct node *current;
	struct node **ptr_to_head = &root;
	int k;

	root = (struct node*)malloc(sizeof(struct node));
	root->next = NULL;
	root->data = NULL;
	current = root;

	for(k = 1; k < 10; k++)
	{
		insert(current, k * 5);
		current = current->next;
	}

	printList(root);

	return 0;
}

int isEmpty(struct node* list)
{
	if(list->next == NULL)
		return 1;
	return 0;
}

void makeEmpty(struct node* list)
{
	list->next = NULL;
}

void printList(struct node *list)
{
	struct node* current;

	if(isEmpty(list))
		printf("List is empty.\n");
	else
	{
		current = list->next;
		while(current->next != NULL)
		{
			printf("%d\n", current->data);
			current = current->next;
		}
		printf("%d\n", current->data);
	}

}

/*returns a node containing the item in the list. If item is
 *not found then a null value is returned
 */

struct node* find(struct node *list, int item)
{
	struct node *p = list->next;
	if(p != NULL)
	{
		while(p->next != NULL)
		{
			if(p->data == item)
				return p;
			p = p->next;
		}
	}

	return NULL;
}

//inserts item at the front of the list

void insert(struct node *list, int item)
{
	if(list != NULL)
	{
		struct node* p = (struct node*)malloc(sizeof(struct node));
		p->data = item;
		p->next = list->next;
		list->next = p;
	}
}

void removeNode(struct node *list, int item)
{
	struct node *current = list->next;
	struct node *previous = list;

	if(isEmpty(list))
		printf("List is empty.");
	else
	{
		while(current->next != NULL && current->data != item)
		{
			previous = current;
			current = current->next;
		}
		if(current->data == item)
		{
			previous->next = current->next;
			free(current);
		}
		else
			printf("Value not in list.\n");
	}
}

ok. I will try and make some improvements. Do you know of a good reference, be it book or website, for implementing linked lists and binary trees in C? My implementation is pretty much based off of my C text book. It is "Engineering Problem Solving with C" by Delores M. Etter. Thanks for your help.

A quick Google search brought up several tutorials of varying quality. This one seemed to be pretty good: http://en.literateprograms.org/Categoryata_structures.