c++ list class, type of node?

exodist · 05-20-2004, 05:37 PM

I have been asked to use objects of type list, what I use them for is upt o me, I am supposed to use an iterator to scan through and print out everythign in at least one list.

my problem is I am trying ot make my iterator and I realise I do not have this required info:

what "Node" type is used in a list type.

as in

Type *interator

as well so far we have been making our own nodes and giving them a pointer called Link to point to the next. is Link the usual name? would the Node type use it? as well I noticed lists can also go backwards, if Link is next what is previous?

I have the oreilly c++ and STl references, a class book, and the C++ STL hardback and I cannot seem to find this info, maybe I do not know where to look, or maybe I have missed the concept here somewhere.. can anyone help me?

exodist · 05-20-2004, 05:55 PM

here is some code: I have placed comments everywhere I need the info for.

Code:

#include <iostream>
#include <string>
#include <cstddef>
#include <cstdlib>
#include <cctype>
#include <cstring>
#include <list> //is this correct?

using namespace std;

int main()
{
	int i = 0;
	/*whatever node type the builtin list type uses?*/ *Iterator;
	list<int> FirstList;

	while (i < 6)
	{
		FirstList.push_back(i);
		i++;
	}

	Iterator = FirstList;
	while (Iterator != NULL)
	{
		cout << Iterator.begin();
		Iterator = Iterator->Link/*or whatever the object used as a node by the list type calls it.*/;
	}

	FirstList.reverse();

	Iterator = FirstList;
	while (Iterator != NULL) //should now print in reverse order
	{
		cout << Iterator.begin();
		Iterator = Iterator->Link/*or whatever the object used as a node by the list type calls it.*/;
	}

	FirstList.sort();

	Iterator = FirstList;
	while (Iterator != NULL) //should now print in sorted order
	{
		cout << Iterator.begin();
		Iterator = Iterator->Link/*or whatever the object used as a node by the list type calls it.*/;
	}
}

exodist · 05-20-2004, 06:27 PM

well, I do not think it is what he wanted, but looking up the iterator type I got this final product that works:
#include <iostream>
#include <string>
#include <cstddef>
#include <cstdlib>
#include <cctype>
#include <cstring>
#include <list>

using namespace std;

int main()
{
int i = 0;
list<int> FirstList;
list<int>::iterator MyIterator;

while (i < 6)
{
FirstList.push_back(i);
i++;
}

cout << endl << "Initial:";
MyIterator = FirstList.begin();
while (MyIterator != FirstList.end())
{
cout << *MyIterator;
MyIterator++;
}

cout << endl << "Reversed:";
FirstList.reverse();
MyIterator = FirstList.begin();
while (MyIterator != FirstList.end())
{
cout << *MyIterator;
MyIterator++;
}

cout << endl << "Sorted:";
FirstList.sort();
MyIterator = FirstList.begin();
while (MyIterator != FirstList.end())
{
cout << *MyIterator;
MyIterator++;
}
cout << endl;
}