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Sorting circular linked list c++

cakehead (3)
Hey! I'm currently having trouble sorting a circular linked list in c++.

I want to sort said linked list, and here's what I've got so far. I'd really appreciate any input regarding anything in the code really, seeing as I'm a beginner at this. I hope you somewhat get an idea what I want to do.

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#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

struct listNode;

typedef listNode* list_type;

struct person 
{
	char lastName[20]; 
	char firstName[20];
	char number[20];
};

struct listNode
{
	person data;
	list_type next;
};

void display(listNode*);
void sort(listNode*);		
	

int main ()
{
	list_type node;
	list_type root = 0;
	node = root;
	int counter = 0;
	
	person info;
	char garb[1];
	ifstream infile ("indata.txt");
	if ( infile.is_open())
	{
		while (infile.good())
		{
			infile.getline(info.lastName,20, ',');
			infile.getline(garb,1, ' ');
			infile.getline(info.firstName,20, ':');
			infile.getline(info.number,20);
			
			if (node == 0)
			{
				node = new listNode;
				node->next = NULL;
				node->data = info;
				counter++;
			}
			else
			{
				node->next = new listNode;
				node = node->next;
				node->data = info;
				node->next = NULL;
				counter++;
			}

		}
		node->next = root;
		
		
		
	
		infile.close();
	}
    else
	{
	cout <<"unable to open file." <<endl;
	}
	display(listNode*);
	sort(listNode*);
	display(listNode*);
    
    return 0;     
   
}

void sort(listNode*)
{
	int counter = 0;
	listNode* = next;
	listNode* = curr;
	listNode* = tmp;
	
	for (int i=0; i < counter; i++)
	{
		for (int j=0; j < counter; j++)
		{
			if(curr->data > curr->next->data)
			{
				tmp->data = curr->data;
				curr->data = curr->next->data;
				curr->next-> = tmp->data;
				counter++
			}
		}
	}
}
	



}

void display(listNode*)
{
	listNode* = curr;
	cout << "Printing.." << endl;
	while(curr != 0)
	{
		cout << curr->data << endl;
		curr = curr->next;
	}
	cout << "..Done!" << endl;



Forgot to mention. The input I get is on this form:
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Kverulando, Kajsa:0123-4567
Allegrettho, Albert:0701-23456
Glissando, Gloria:0234-5678
Hysterico, Hilding:013-1234
Presto, Pelle:013-1243


I want:
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Allegrettho Albert 0701-23456
Glissando Gloria 0234-5678
Hysterico Hilding 013-1234
Kverulando Kajsa 0123-4567
Presto Pelle 013-1243


As you can see it's supposed to sort on the lastname first, and then firstname, and last the number.
Last edited on
hamsterman (4538)
You fail to sort a circular list because there is no such thing as a sorted circular list (except for a list with all items equal). A list is sorted if X->data >= X->next->data for all nodes X. Thus root->data >= root->next->data >= root->next->next->...->next->data == root.data

That aside, I have no idea what your sort is trying to do? Which sorting algorithm are you trying to implement?
Last edited on
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