Sorting in Linked List

Waleed Azam (14)
Can anyone please help me that how do I do sorting in a linked list? I have to use Bubble Sort to done my assignment.
Waleed Azam (14)
This is the sorting part of the code.

void sorting ()
{
ListNode * temphead = head;
ListNode * tempnode = NULL;
int counter = 0;
while (temphead)
{
temphead = temphead->next;
counter++;
}
for (int i=0; i<counter; i++)
{
for (int j=0; j<counter-i; j++)
{
if (temphead->roll > temphead->next->roll)
{
tempnode = temphead;
temphead = temphead->next;
temphead->next = tempnode;
}
}
}
}
chipp (776)
the others probably want to see the full code, and please use [code] [/code] tag
naraku9333 (2163)
It might be easier (conceptually) to swap the node data rather than the nodes themselves.
Waleed Azam (14)
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#include<iostream>
#include<string>
#include<stdlib.h>
using namespace std;
struct ListNode
{
	string name;
	int roll;
	ListNode * next;
};
ListNode * head = NULL;
void append (string, int);
void insertname (string, int);
void insertroll (string, int);
void deletenode (int);
void deletenode (string);
void deleteall ();
void printing ();
void sorting ();
void exitprog ();
void main ()
{
	int select, roll, num;
	string name;
	while (1)
	{
		cout<<"Press 1 for appending the node"<<endl;
		cout<<"Press 2 for inserting the node"<<endl;
		cout<<"Press 3 for deleting the node"<<endl;
		cout<<"Press 4 for deleting the list"<<endl;
		cout<<"Press 5 for printing the list"<<endl;
		cout<<"Press 6 for sorting the list"<<endl;
		cout<<"Press 7 to exit the program"<<endl;
		cin>>select;
		switch (select)
		{
		case 1:
			cout<<"Please enter the name of the student: ";
			cin.ignore (10000,'\n');
			getline (cin, name);
			cout<<"Please enter the roll number of the student: ";
			cin>>roll;
			append (name, roll);
			break;
		case 2:
			cout<<"Press 1 to sort on the basis of name or 2 to sort on the basis of roll number: ";
			cin>>num;
			cout<<"Please enter the name of the student: ";
			cin.ignore (10000,'\n');
			getline (cin, name);
			cout<<"Please enter the roll number of the student: ";
			cin>>roll;
			if (num == 1)
			{
				insertname (name, roll);
			}
			else if (num == 2)
			{
				insertroll (name, roll);
			}
			break;
		case 3:
			cout<<"Press 1 to delete the node on the basis of name or 2 to delete on the basis of roll number: ";
			cin>>num;
			if (num == 1)
			{
				string value;
				cout<<"Please enter the name: ";
				cin.ignore (10000,'\n');
				getline (cin, value);
				deletenode (value);
			}
			else if (num == 2)
			{
				int value;
				cout<<"Please enter the roll number: ";
				cin>>value;
				deletenode (value);
			}
			else
			{
				cout<<"You have entered an invalid input...!"<<endl;
			}
			break;
		case 4:
			deleteall ();
			break;
		case 5:
			printing ();
			break;
		case 6:
			sorting ();
			break;
		case 7:
			exitprog ();
		default:
			cout<<"You have entered an invalid input...!"<<endl;
			break;
		}
	}
}
void append (string name, int roll)
{
	ListNode * temphead = head;
	ListNode * temp = new ListNode;
	temp->name = name;
	temp->roll = roll;
	temp->next = NULL;
	if (head == NULL)
	{
		head = temp;	
	}
	else
	{
		while (temphead->next)
		{
			temphead = temphead->next;
		}
		temphead->next = temp;
	}
}
void insertname (string name, int roll)
{
	ListNode * temp = new ListNode;
	temp->next = NULL;
	temp->name = name;
	temp->roll = roll;
	if (head == NULL)
	{
		head = temp;
	}
	else
	{
		ListNode * temphead = head;
		ListNode * previous = NULL;
		while (temphead != NULL && name > temphead->name)
		{
			previous = temphead;
			temphead = temphead->next;
		}
		if (previous == NULL)
		{
			head = temp;
			temp->next = temphead;
		}
		else if (temphead == NULL)
		{
			previous->next = temp;
		}
		else
		{
			previous->next = temp;
			temp->next = temphead;
		}
	}
}
void insertroll (string name, int roll)
{
	ListNode * temp = new ListNode;
	temp->next = NULL;
	temp->name = name;
	temp->roll = roll;
	if (head == NULL)
	{
		head = temp;
	}
	else
	{
		ListNode * temphead = head;
		ListNode * previous = NULL;
		while (temphead != NULL && roll > temphead->roll)
		{
			previous = temphead;
			temphead = temphead->next;
		}
		if (previous == NULL)
		{
			head = temp;
			temp->next = temphead;
		}
		else if (temphead == NULL)
		{
			previous->next = temp;
		}
		else
		{
			previous->next = temp;
			temp->next = temphead;
		}
	}
}
void deletenode (int roll)
{
	ListNode * temphead = head;
	ListNode * previous = NULL;
	ListNode * tempnext = NULL;
	while (temphead->roll != roll && temphead != NULL)
	{
		previous = temphead;
		temphead = temphead->next;
	}
	if (temphead == NULL)
	{
		cout<<"Sorry no data found!!!"<<endl;
	}
	else if (previous == NULL)
	{
		tempnext = temphead->next;
		head = tempnext;
		delete temphead;
	}
	else
	{
		tempnext = temphead->next;
		previous->next = tempnext;
		delete temphead;
	}
}
void deletenode (string name)
{
	ListNode * temphead = head;
	ListNode * previous = NULL;
	ListNode * tempnext = NULL;
	while (temphead->name != name && temphead != NULL)
	{
		previous = temphead;
		temphead = temphead->next;
	}
	if (temphead == NULL)
	{
		cout<<"Sorry no data found!!!"<<endl;
	}
	else if (previous == NULL)
	{
		tempnext = temphead->next;
		head = tempnext;
		delete temphead;
	}
	else
	{
		tempnext = temphead->next;
		previous->next = tempnext;
		delete temphead;
	}
}
void deleteall()
{
	ListNode * temphead = head, * temp;
	while (temphead)
	{
		temp = temphead->next;
		delete temphead;
		temphead = temp;
	}
	head = NULL;
}
void printing ()
{
	if (head == NULL)
	{
		cout<<"There is nothing to print."<<endl;
		return;
	}
	ListNode * temphead = head;
	while (temphead)
	{
		cout<<temphead->name<<' '<<temphead->roll<<endl;
		temphead = temphead->next;
	}
}
void sorting ()
{
	ListNode * temphead = head;
//	ListNode * tempnode = NULL;
	int temproll;
	string tempname;
	int counter = 0;
	while (temphead)
	{
		temphead = temphead->next;
		counter++;
	}
	for (int i=0; i<counter; i++)
	{
		for (int j=0; j<counter-i; j++)
		{
			if (temphead->roll > temphead->next->roll)
			{
//				tempnode = temphead;
//				temphead = temphead->next;
//				temphead->next = tempnode;
				temproll = temphead->roll;
				temphead->roll = temphead->next->roll;
				temphead->next->roll = temproll;

				tempname = temphead->name;
				temphead->name = temphead->next->name;
				temphead->next->name = tempname;
			}
		}
	}
}
void exitprog ()
{
	exit (0);
}
Waleed Azam (14)
naraku9333 i have tried to sort through values but its still not working. I have problem just in sorting. Otherwise whole code is running smoothly perfect.
naraku9333 (2163)
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void sorting ()
{
	ListNode * temphead = head;
	//ListNode * tempnode = NULL;
	int temproll;
	string tempname;
	int counter = 0;
	while (temphead)
	{
		temphead = temphead->next;
		counter++;
	}
	temphead = head;
	
	for (int j=0; j<counter; j++)
	{
		while (temphead->next)  //iterate through list until next is null
		{
			if (temphead->roll > temphead->next->roll)
			{
				/*tempnode = temphead;
				temphead = temphead->next;
				temphead->next = tempnode;*/
				temproll = temphead->roll;
				temphead->roll = temphead->next->roll;
				temphead->next->roll = temproll;

				tempname = temphead->name;
				temphead->name = temphead->next->name;
				temphead->next->name = tempname;
				temphead = temphead->next;//increment node
			}
			else 
				temphead = temphead->next;//increment node
		}	
		temphead = head;//reset temphead
	}
}

Waleed Azam (14)
Thank you very much. I shall always be thankful to you.
Waleed Azam (14)
This is the switch case part.
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		case 6:
			cout<<"Press 1 to sort in ascending order or 2 to sort in descending order: ";
			cin>>num;
			if (num == 1)
			{
				cout<<"Press 1 to sort on the basis of name or 2 to sort on the basis of roll number: ";
				cin>>num2;
				if (num2 == 1)
				{
					asc_name_sorting ();
				}
				else if (num2 == 2)
				{
					asc_roll_sorting ();
				}
				else
				{
					cout<<"You have entered an invalid input...!"<<endl;
				}
			}
			else if (num == 2)
			{
				cout<<"Press 1 to sort on the basis of name or 2 to sort on the basis of roll number: ";
				cin>>num2;
				if (num2 == 1)
				{
					des_name_sorting ();
				}
				else if (num2 == 2)
				{
					des_roll_sorting ();
				}
				else
				{
					cout<<"You have entered an invalid input...!"<<endl;
				}
			}
			else
			{
				cout<<"You have entered an invalid input...!"<<endl;
			}
			asc_roll_sorting ();
			break;

This is the implementations functions.
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void asc_name_sorting ()
{
	ListNode * temphead = head;
	int temproll;
	string tempname;
	int counter = 0;
	while (temphead)
	{
		temphead = temphead->next;
		counter++;
	}
	temphead = head;
	
	for (int j=0; j<counter; j++)
	{
		while (temphead->next)
		{
			if (temphead->name > temphead->next->name)
			{
				temproll = temphead->roll;
				temphead->roll = temphead->next->roll;
				temphead->next->roll = temproll;

				tempname = temphead->name;
				temphead->name = temphead->next->name;
				temphead->next->name = tempname;
			}
			temphead = temphead->next;
		}	
		temphead = head;
	}
}
void asc_roll_sorting ()
{
	ListNode * temphead = head;
	int temproll;
	string tempname;
	int counter = 0;
	while (temphead)
	{
		temphead = temphead->next;
		counter++;
	}
	temphead = head;
	
	for (int j=0; j<counter; j++)
	{
		while (temphead->next)
		{
			if (temphead->roll > temphead->next->roll)
			{
				temproll = temphead->roll;
				temphead->roll = temphead->next->roll;
				temphead->next->roll = temproll;

				tempname = temphead->name;
				temphead->name = temphead->next->name;
				temphead->next->name = tempname;
			}
			temphead = temphead->next;
		}	
		temphead = head;
	}
}
void des_name_sorting ()
{
	ListNode * temphead = head;
	int temproll;
	string tempname;
	int counter = 0;
	while (temphead)
	{
		temphead = temphead->next;
		counter++;
	}
	temphead = head;
	
	for (int j=0; j<counter; j++)
	{
		while (temphead->next)
		{
			if (temphead->name < temphead->next->name)
			{
				temproll = temphead->roll;
				temphead->roll = temphead->next->roll;
				temphead->next->roll = temproll;

				tempname = temphead->name;
				temphead->name = temphead->next->name;
				temphead->next->name = tempname;
			}
			temphead = temphead->next;
		}	
		temphead = head;
	}
}
void des_roll_sorting ()
{
	ListNode * temphead = head;
	int temproll;
	string tempname;
	int counter = 0;
	while (temphead)
	{
		temphead = temphead->next;
		counter++;
	}
	temphead = head;
	
	for (int j=0; j<counter; j++)
	{
		while (temphead->next)
		{
			if (temphead->roll < temphead->next->roll)
			{
				temproll = temphead->roll;
				temphead->roll = temphead->next->roll;
				temphead->next->roll = temproll;

				tempname = temphead->name;
				temphead->name = temphead->next->name;
				temphead->next->name = tempname;
			}
			temphead = temphead->next;
		}	
		temphead = head;
	}
}

Now the problem is that the sorting is not going perfect. It is just sorting in ascending order of roll numbers every time, and I have to do sorting in ascending order as well as in descending order. And on the basis of both name and roll number.
Waleed Azam (14)
Oops sorry it was an extra line in the end of case part. Thanks :)
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