Trying to built linked list...need help!

[munjo5746]

I am trying to build a linked list but I keep having trouble with it!!
Please correct my code!!

#include <iostream>
#include "linked_list.h"

using std::cout;

node::node(){
	head = NULL;
	next = NULL;
	data = 0;
}


node::~node(){

	for(node* current = head; current != NULL; current = current->next){
		delete current;
	}
}
void node::insert(int value){
	if(head == NULL){
		node* ptr = new node();
		head = ptr;
		ptr->data = value;
		head->next = NULL;
	}
	else{
		node* ptr = new node();
		next = ptr;
		ptr->data = value;
		ptr->next = NULL;
	}

}
void node::show(){
	for(node* current = head; current != NULL; current = current->next){
		cout<<current->data<<"\t";
	}
}

There is a header file called linked_list.h!!!

[ne555]

http://www.cplusplus.com/forum/articles/40071/#msg218019

for(node* current = head; current != NULL; current = current->next){
	delete current;
}

You are trying to access the object that just got destroyed.


¿what are you trying to do in line 28?

[Hucaru]

Can you please include the header file as well so we can see the structure of the list and nodes.

[Lowest0ne]

You don't want to delete the whole list in the node's destructor, else you can't remove a node.

struct node
{
 int data;
 node*next;

 node(int d, node* n) :data(d), next(n) {}
];

List's that have a "push_back" function typically have a "tail" as well as head:

if (!head)
 head = new node(value, NULL);
else if (!tail)
 tail = head->next = new node(value, NULL);
else
 tail = tail->next = new node(value, NULL);

For beginning, "push_front" is easier:
head = new node(value, head);

[ne555]

> You don't want to delete the whole list in the node's destructor, else you can't remove a node.
You can, you just need to `unlink' it first.
But it's a good catch, you are also causing an stack overflow


If you use a header cell (instead of a pointer) `push_back()' simplifies

void list::push_back(const T &item){
   last->next = new node(item, &head); //circular
   last = last->next;
}

list::list(),
   last(&head)
{
   head.next = &head; //circular
}