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Bubblesorting a Linked list

Filthy McNasty (3)
Hello all,
I have been given 2 sets of numbers from a file.

Set 1) 25 15 45 35 65 55

Set 2) 29 23 12 39 32 37 41 52 67 59 103 91

I need to take a set of numbers from a file and place into a linked list (using an operator), Bubble Sort the Linked list then output the set to a file in ascending order (using an operator). Here's what I have so far. There are no problems, it compiles. Yet, it won't sort at all. In the bubblesort function, I am trying to move my pointer *end to the end of the linked list and the pointer *prev right behind *end, so it can bubblesort from the end of the list to the front. Thanks for your time and help. 

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  My .h file
#include <iostream>
#include <fstream>
#include <cstdlib>

using namespace std;

struct nodeType  //struct for linked list
{
       int info;
       nodeType *link;
};


class Bubble
{
      
      public:
             Bubble();  //Default constructor
             ~Bubble(); //Destructor
             int size() const;
             Bubble(const Bubble & inclass); //Copy constructor
             friend istream & operator>>(istream &infile, Bubble & inclass);
             friend ostream & operator<<(ostream &myfile, const Bubble & outclass);
             const Bubble& operator=(const Bubble& otherlist);
             void Bubblesort();
      private:
             nodeType * head_ptr;
             int manynodes;       
};

void list_clear(nodeType* &head_ptr);
void reverselist(nodeType* &mylist);


My .cpp file

#include <iostream>
#include <cstdlib>
#include "Bubble.h"

using namespace std;

void Bubble::Bubblesort()
{
     
     int temp, x;
     nodeType *beg, *follow, *end, *prev;
     int iteration=1;
     bool noexchanges = false;
     beg = head_ptr;
     end = head_ptr;
             
     while(!noexchanges && end->link != NULL)
     {
        noexchanges=true;
        while (iteration<manynodes)
        {
             prev=end;
             end=end->link;
             if(end->link == NULL)
             {
             cout<<endl;                          
             cout<<iteration<<" doesn't work.  No way man!"<<endl;
             cout<<endl;
             }
             iteration++;
        }
        follow = head_ptr->link;
        //prev=end;
        end=end->link;      
        for(x=0; x<iteration-manynodes; x++)
        { 
             if ((prev->info) > (end->info))
              {
              temp=prev->info;
              prev->info=end->info;
              end->info=temp;
              noexchanges=false;
              }
              iteration++;
              follow=follow->link;
              prev=follow;
              //end=prev;
              
        } // inner loop
        end = prev;
     } // outer while loop
}

istream& operator>>(istream & infile, Bubble & inclass)
{
                
        nodeType *follow, *beg,*end;
        int tempnum;
        list_clear(inclass.head_ptr);
        inclass.head_ptr=NULL;
        beg, end=NULL;
        infile>>tempnum;
              
        while (infile)
        {
          follow = new nodeType;
          follow->info=tempnum;
          follow->link=NULL;
          if (inclass.head_ptr==NULL)
          {
              inclass.head_ptr=follow;
          }
          else
          {
              end->link=follow;
          }
          end=follow;
          infile>>tempnum;
          inclass.manynodes++; 
        }
        cout<<endl;
        return infile;
        
}

ostream& operator<<(ostream & myfile, const Bubble & outclass)
{
         
         nodeType *current;
         current=outclass.head_ptr;
         while(current != NULL)
         {
         myfile<<current->info<<" ";
         cout<<current->info<<" ";
         current=current->link;
         }
         return myfile;   
         
}

Bubble::Bubble() //Constructor
{
    manynodes=0;
    head_ptr = NULL;
}

Bubble::Bubble(const Bubble & inclass) //Copy constructor
{
    nodeType *tail_ptr;
    //list_copy(inclass.head_ptr,head_ptr,tail_ptr);
}

Bubble::~Bubble() //Destructor
{
    list_clear(head_ptr);
}

const Bubble& Bubble::operator=(const Bubble& otherlist)
{
    nodeType *tail_ptr;
    if(this != &otherlist)
    list_clear(head_ptr); 
    //list_copy(otherlist.head_ptr, head_ptr, tail_ptr);
    return otherlist;
}

void list_clear(nodeType* & head_ptr)
{
     nodeType * removeptr;
     while(head_ptr != NULL)
     {
     removeptr = head_ptr;
     head_ptr = head_ptr->link;
     delete removeptr;
     }
}

void reverselist (nodeType * mylist)
{
     nodeType* templist;
     nodeType* tempnode;
     templist=NULL;
     while (mylist!= NULL)
     {
           tempnode = mylist;
           mylist= mylist->link;
           tempnode->link = templist;
           templist=tempnode;
     }
     mylist=templist;
}

My main

#include <iostream>
#include <cstdlib>
#include <fstream>
#include "Bubble.cpp"

using namespace std;

int main()
{
    ofstream myfile;  //interface to write data to files.
    ifstream yourfile;  //interface to gather data from files.
    yourfile.open("bubble input.txt"); // where the data is coming from
    myfile.open("bubble output.txt"); //where the data is going to
    myfile<<"Lab CSC"<<endl;
    
    Bubble number1;    
    
        
        cout<<number1<<endl;
        
        while(yourfile)
        { 
        yourfile>>number1;              
        myfile<<number1<<endl;
        number1.Bubblesort();
        myfile<<number1<<endl;    
        }
                
        yourfile.close();
        myfile.close();
               
        cout<<endl;
        cout<<endl;
       

    cout<<"Goodbye."<<endl;
    system ("pause");
    cout<<endl;
    return 0;
}
Smac89 (1727)
Can you please explain the algorithm you are using in your bubble sort. What does the input look like and what is the body of the function doing?
Filthy McNasty (3)
No input from user, sets of numbers came from a .txt file. Used the >> operator to bring them in and place them into a linked list.

I start the *end pointer at the head pointer (head_ptr, given by the class) of the linked list and used the 2nd while loop to move the *end pointer to the end of the linked list and the *prev pointer right behind it.

The for loop, controlled by the length of the linked list, traverses the linked list, backwards. The If statement compares the two integers where *prev and *end is pointing to, respectively. If prev->info is bigger than end->info, then prev->info and end->info switch values with the help of temp. Then both pointers move 1 spot to the left, all the way to the beginning. At the end of the function, *end and *prev should both be at the head pointer and the linked list should be sorted lowest to highest.
Smac89 (1727)
main

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#include "Bubble.cpp"

using namespace std;

int main()
{
   ofstream myfile;  //interface to write data to files.
   ifstream yourfile;  //interface to gather data from files.
   yourfile.open("bubble input.txt"); // where the data is coming from
   myfile.open("bubble output.txt"); //where the data is going to
   myfile<<"Lab CSC"<<endl;
   
   Bubble number1;    
   
   
   cout<<number1<<endl;
   
   while(yourfile)
   { 
      yourfile>>number1;              
      myfile<<number1<<endl;
      number1.Bubblesort();
      myfile << "\nSorted list....\n";
      myfile<<number1<<endl;    
   }
   
   yourfile.close();
   myfile.close();
   
   cout<<endl;
   cout<<endl;
   
   
   cout<<"Goodbye."<<endl;
   cout<<endl;
   return 0;
}



bubble.h

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#include <iostream>
#include <cstdio>
#include <fstream>
#include <cstdlib>
#include <algorithm>

using namespace std;

struct nodeType  //struct for linked list
{
       int info;
       nodeType *link;
};


class Bubble
{
      
      public:
             Bubble();  //Default constructor
             ~Bubble(); //Destructor
             int size() const;
             Bubble(const Bubble & inclass); //Copy constructor
             friend istream & operator>>(istream &infile, Bubble & inclass);
             friend ostream & operator<<(ostream &myfile, const Bubble & outclass);
             const Bubble& operator=(const Bubble& otherlist);
             void Bubblesort();
      private:
             nodeType * head_ptr;
             int manynodes;       
};

void list_clear(nodeType* &head_ptr);
void reverselist(nodeType* &mylist);


bubble.cpp

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#include "Bubble.h"

using namespace std;

void Bubble::Bubblesort()
{
   nodeType *follow, *end, *prev;
   bool exchanges = true;
   end = head_ptr;
   
   while( exchanges )
   {
      exchanges = false;
      
      prev = end;
      follow = prev->link;
      while ( follow )
      { 
	 if ((prev->info) > (follow->info))
	 {
	    swap( prev->info, follow->info );
	    exchanges = true;
	 }
	 prev = prev->link;
	 follow = prev->link;	 
      }
   }
}

istream& operator>>(istream & infile, Bubble & inclass)
{
   
   nodeType *follow,*end;
   int tempnum;
   list_clear(inclass.head_ptr);
   inclass.head_ptr=NULL;
   end=NULL;
   infile>>tempnum;
   
   while (infile)
   {
      follow = new nodeType;
      follow->info=tempnum;
      follow->link=NULL;
      if (inclass.head_ptr==NULL)
      {
	 inclass.head_ptr=follow;
      }
      else
      {
	 end->link=follow;
      }
      end=follow;
      infile>>tempnum;
      inclass.manynodes++; 
   }
   cout<<endl;
   return infile;
   
}

ostream& operator<<(ostream & myfile, const Bubble & outclass)
{
   
   nodeType *current;
   current=outclass.head_ptr;
   while(current != NULL)
   {
      myfile<<current->info<<" ";
      cout<<current->info<<" ";
      current=current->link;
   }
   return myfile;   
   
}

Bubble::Bubble() //Constructor
{
   manynodes=0;
   head_ptr = NULL;
}

Bubble::Bubble(const Bubble & inclass) //Copy constructor
{
   //nodeType *tail_ptr;
   //list_copy(inclass.head_ptr,head_ptr,tail_ptr);
}

Bubble::~Bubble() //Destructor
{
   list_clear(head_ptr);
}

const Bubble& Bubble::operator=(const Bubble& otherlist)
{
   //nodeType *tail_ptr;
   if(this != &otherlist)
      list_clear(head_ptr); 
   //list_copy(otherlist.head_ptr, head_ptr, tail_ptr);
      return otherlist;
}

void list_clear(nodeType* & head_ptr)
{
   nodeType * removeptr;
   while(head_ptr != NULL)
   {
      removeptr = head_ptr;
      head_ptr = head_ptr->link;
      delete removeptr;
   }
}

void reverselist (nodeType * mylist)
{
   nodeType* templist;
   nodeType* tempnode;
   templist=NULL;
   while (mylist!= NULL)
   {
      tempnode = mylist;
      mylist= mylist->link;
      tempnode->link = templist;
      templist=tempnode;
   }
   mylist=templist;
}


output

Lab CSC
25 15 45 35 65 55 29 23 12 39 32 37 41 52 67 59 103 91 

Sorted list....
12 15 23 25 29 32 35 37 39 41 45 52 55 59 65 67 91 103


When I get back from work, I will show you an optimized version of the sorting
Last edited on
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