Find an item in the LinkedList (C++)

[harsha_123]

I'm new to c++. I was studying data structures and came to know Linked Lists Lately.
We had a problem of finding an item stored inside a linked list and here's the code I wrote using Visual Studio to store and find an item. This code gives me a run time error.

1. "Link.h" file

#pragma once

class Link
{
public:
	double num;
	char nam[20];
	Link* next;
	Link(double pnum,char pnam[]);
	void displayLink();
};

2. "Link.cpp" file

#include "StdAfx.h"
#include "Link.h"
#include<iostream>
#include<cstring>
using namespace std;

Link::Link(double pnum,char pnam[])
{
	next = NULL;
	num = pnum;
	strcpy(nam,pnam);
}

void Link::displayLink()
{
	cout<<num<<"\t"<<nam<<endl;
}

3. "LinkList.h" file

#pragma once
#include"Link.h"

class LinkList
{
private:
	Link *first;

public:
	LinkList();
	void insertFirst(double n,char nm[]);
	Link* find(double n);
};

4. "Linklist.h" file

#include "StdAfx.h"
#include "LinkList.h"
#include"Link.h"
#include<iostream>
using namespace std;

LinkList::LinkList()
{
	first = NULL;
}

void LinkList::insertFirst(double n,char nm[])
{
	Link *temp = new Link(n,nm);
	temp->next = first;
	first = temp;
	cout<<"DATA ENTERED"<<endl;
}

Link* LinkList::find(double n)
{
	Link *cur = first;
	while(cur!=NULL)
	{
		if(cur->num == n)
		{
			return cur;
		}
		else
		{
			cur = cur->next;
		}
	}
	return NULL;

}

5."LinkList_5.cpp" (main program)

#include "stdafx.h"
#include<iostream>
#include"Link.h"
#include"LinkList.h"
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
	LinkList *ne = new LinkList();
	ne->insertFirst(12.22,"Charith");
	ne->insertFirst(13.22,"Lalitha");
	cout<<ne->find(12.22)->num;

	system("PAUSE");
	return 0;
}

I've doubt about the way I accessed items that're returned by 'find' method. Can somebody please tell me a way of getting out values returned in that particular method inside the LinkList_5.cpp.

[mahesh113]

Floats and doubles can't be compared using relational operators. That may be the issue. you can search web for how to compare floats.

I'm new to c++. I was studying data structures and came to know Linked Lists Lately. We had a problem of finding an item stored inside a linked list and here's the code I wrote using Visual Studio to store and find an item. This code gives me a run time error.

1. "Link.h" file

#pragma once

class Link
{
public:
	double num;
	char nam[20];
	Link* next;
	Link(double pnum,char pnam[]);
	void displayLink();
};

2. "Link.cpp" file

#include "StdAfx.h"
#include "Link.h"
#include<iostream>
#include<cstring>
using namespace std;

Link::Link(double pnum,char pnam[])
{
	next = NULL;
	num = pnum;
	strcpy(nam,pnam);
}

void Link::displayLink()
{
	cout<<num<<"\t"<<nam<<endl;
}

3. "LinkList.h" file

#pragma once
#include"Link.h"

class LinkList
{
private:
	Link *first;

public:
	LinkList();
	void insertFirst(double n,char nm[]);
	Link* find(double n);
};

4. "Linklist.h" file

#include "StdAfx.h"
#include "LinkList.h"
#include"Link.h"
#include<iostream>
using namespace std;

LinkList::LinkList()
{
	first = NULL;
}

void LinkList::insertFirst(double n,char nm[])
{
	Link *temp = new Link(n,nm);
	temp->next = first;
	first = temp;
	cout<<"DATA ENTERED"<<endl;
}

Link* LinkList::find(double n)
{
	Link *cur = first;
	while(cur!=NULL)
	{
		if(cur->num == n)
		{
			return cur;
		}
		else
		{
			cur = cur->next;
		}
	}
	return NULL;

}

5."LinkList_5.cpp" (main program)

#include "stdafx.h"
#include<iostream>
#include"Link.h"
#include"LinkList.h"
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
	LinkList *ne = new LinkList();
	ne->insertFirst(12.22,"Charith");
	ne->insertFirst(13.22,"Lalitha");
	cout<<ne->find(12.22)->num;

	system("PAUSE");
	return 0;
}

I've doubt about the way I accessed items that're returned by 'find' method. Can somebody please tell me a way of getting out values returned in that particular method inside the LinkList_5.cpp.

[harsha_123]

Thanks for the reply! But, here I want to display both name and decimal number of the person who's being searched by the user of the program is there a way to do that!