Thread: linked list help me

lets say amount has been passed a value any value now I want to
make a linked list of size amount, How do I go about making the
cin statements enter data into each node for each iteration and
the following code is what i've got.

Code:

void new_node(int amount)
{

    int loop;
	node *top; // pointer of type node

    for(loop=0;loop<amount;loop++)
    	{
            top=new node; // ptr top points to spare memory, the size of node

            cout<<"Enter persons name >";
            cin>>top->name;

            cout<<'\n'<<"Enter persons age >";
            cin>>top->age;

            top->next=new node; // The pointer next in the first node now
               // points to the next node with new setting the memory aside
        }
}

You have no way of returning the allocated list back to the calling program. I modified your function to take a pointer to the head of the list:

Code:

void new_node(node* top, int amount)
{

	int loop;
	node* iterator = top;

 	for(loop=0;loop<amount;loop++)
    	{
            iterator->next = new node; // ptr top points to spare memory, the size of node
            iterator = iterator->next;

            cout<<"Enter persons name >";
            cin>> iterator->name;

            cout<<'\n'<<"Enter persons age >";
            cin>> iterator->age;
        }
}

That code is untested, but it should work.

ok ripper.

for an amount of people then create a linked list
for that amount of people ie if you input 15 I
want a linked list of 15 structures(nodes) and the
for loop to accept the input for each node.

also how would I free the memory in a different for loop

Code:

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>

#define MAX 30


	struct node{
                    int age;
                    char name[MAX];
                    node *next;
               };

int main()
{
    int amount;

    cout<<"How many people to be stored >";
    cin>>amount;

    if(amount==0)
    	exit(1);

    void new_node(int amount);

    getch();

    return 0;
}


void new_node(int amount)
{

    int loop;
	node *top; // pointer of type node

    for(loop=0;loop<amount;loop++)
    	{
            top=new node; // ptr top points to spare memory, the size of node

            cout<<"Enter persons name >";
            cin>>top->name;

            cout<<'\n'<<"Enter persons age >";
            cin>>top->age;

            top->next=new node; // The pointer next in the first node now
               // points to the next node with new setting the memory aside
        }
}

Originally posted by anthonye
ok ripper.

for an amount of people then create a linked list
for that amount of people ie if you input 15 I
want a linked list of 15 structures(nodes) and the
for loop to accept the input for each node.

also how would I free the memory in a different for loop

Code:

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>

#define MAX 30


	struct node{
                    int age;
                    char name[MAX];
                    node *next;
               };

int main()
{
    int amount;

    cout<<"How many people to be stored >";
    cin>>amount;

    if(amount==0)
    	exit(1);

    void new_node(int amount);

    getch();

    return 0;
}


void new_node(int amount)
{

    int loop;
	node *top; // pointer of type node

    for(loop=0;loop<amount;loop++)
    	{
            top=new node; // ptr top points to spare memory, the size of node

            cout<<"Enter persons name >";
            cin>>top->name;

            cout<<'\n'<<"Enter persons age >";
            cin>>top->age;

            top->next=new node; // The pointer next in the first node now
               // points to the next node with new setting the memory aside
        }
}

To free the memory, you need to return the allocated memory back to the calling program (like I showed in an earlier post)

Is this prog fine and if so how would I go about
freeing memory set up for the nodes in a seperate function

also why is it a bad idea to store data in the top node.

Code:

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>

#define MAX 30

void new_node(node *top,int amount);

	struct node{
                    int age;
                    char name[MAX];
                    node *next;
               };

int main()
{
    int amount;
    node *top;

    cout<<"How many people to be stored >";
    cin>>amount;

    if(amount==0)
    	exit(1);

    top=new node // memory set aside for the top node

    void new_node(node *top,int amount); // pass top node and amount to function

    getch();

    return 0;
}


void new_node(node *top,int amount)
{

    int loop;
	node *new_node=top; // pointer of type node points to the top node

    for(loop=0;loop<amount;loop++)
    	{
            new_node->next=new node; // ptr new_node points to spare memory, the size of node(the loop node)
            new_node=new_node->next; // ptr new_node now points to the next element in the loop node

            cout<<"Enter persons name >";
            cin>>new_node->name;            // Enter name in second node

            cout<<'\n'<<"Enter persons age >";
            cin>>new_node->age;             // Enter age in second node

        }

    new_node->next=NULL;
}

PLEASE PLEASE PLEASE try to keep my prog like it is
as this is my first linked list and trying to get used to them.

just solve my questions for now.

thanks guys.