Sorting a Linked List [closed]

Posted by Mohit Sehgal on Programmers See other posts from Programmers or by Mohit Sehgal
Published on 2012-11-14T11:11:41Z Indexed on 2012/11/14 11:17 UTC
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I want to sort a linked list. Here Node is class representing a node in a Linked List I have written a code to bubble sort a linked list. Program does not finishes execution. Kindly point out the mistakes.

class Node
{
      public:
      int data;
     public:
             Node *next;
      Node()
      {
            data=0;next=0;
      }
      Node(int d)
      {
               data=d;
      }
      void setData(int d)
      {
           data=d;
      }
      void print()
      {
           cout<<data<<endl;            
      }
      bool operator==(Node n)
      {
              return this->data==n.data;
      }
      bool operator >(Node d)
      {
           if((this->data) > (d.data))
           return true;

           return false;
      }
};
class LList
{
      public:
             int noOfNodes;
             Node  *start;/*Header Node*/
      LList()
      {
             start=new Node;
             noOfNodes=0;start=0;
      }
      void addAtFront(Node* n)
      {
         n->next=(start);
         start=n;
         noOfNodes++;
      }     
      void addAtLast(Node* n)
      {
           Node *cur=(start);
           n->next=NULL;
           if(start==NULL)
           {
                           start=n;
                           noOfNodes++;
                           return;
           }
           while(cur->next!=NULL)
           {

                           cur=cur->next;
           }
           cur->next=n;
           noOfNodes++;
      }
      void addAtPos(Node *n,int pos)
      {

           if(pos==1)
           {
                     addAtFront(n);return;
           }
           Node *cur=(start);
           Node *prev=NULL;
           int curPos=0;
           n->next=NULL;
           while(cur!=NULL)
           {
                  curPos++;
                  if(pos==curPos+1)
                  {
                                   prev=cur;
                  }
                  if(pos==curPos)
                  {
                                 n->next=cur;
                                 prev->next=n;
                                 break;
                  }
                  cur=cur->next;
           }
           noOfNodes++;
      }
      void removeFirst()
      {

          Node *del=start;
          start=start->next;
          delete del;
          noOfNodes--;
          return;
      }
      void removeLast()
      {
           Node *cur=start,*prev=NULL;
           while(cur->next!=NULL)
           {
              prev=cur;
              cur=cur->next;

           }
           prev->next=NULL;
           Node *del=cur->next;
           delete del;
           noOfNodes--;
           return;
      }
      void removeNodeAt(int pos)
      {
           if(pos<1)
                    return;
           if(pos==1)
                    { removeFirst();return;}
           int curPos=1;
           Node* cur=start->next;
           Node* prev=start;
           Node* del=NULL;
           while(curPos<pos&&cur!=NULL)
           {
                  curPos++;
                  if(curPos==pos)
                  {
                       del=cur;
                       prev->next=cur->next;
                       cur->next=NULL;
                       delete del;
                       noOfNodes--;
                       break;
                  }
                  prev=prev->next;
                  cur=cur->next;
           }

      }
      void removeNode(Node *d)
      {

           Node *cur=start;
           if(*d==*cur)
           {
                       removeFirst();return;
           }
           cur=start->next;
           Node *prev=start,*del=NULL;
           while(cur!=NULL)
           {
                           if(*cur==*d)
                           {
                                       del=cur;
                                       prev->next=cur->next;
                                       delete del;
                                       noOfNodes--;
                                       break;
                           }
                           prev=prev->next;
                           cur=cur->next;
           }
      }
      int getPosition(Node data)
      {
          int pos=0;
          Node *cur=(start);
       while(cur!=NULL)
       {

           pos++;
          if(*cur==data)
         {
           return pos;
         }
         cur=cur->next;
       }
            return -1;//not found
      }
      Node getNode(int pos)
      {
           if(pos<1)
                    return -1;// not a valid position
           else if(pos>noOfNodes)
                return -1; // not a valid position
           Node *cur=(start);
           int curPos=0;
           while(cur!=NULL)
           {
                           if(++curPos==pos)
                                            return *cur;
                           cur=cur->next;
           }
      }
      void reverseList()//reverse the list
      {
           Node* cur=start->next;
            Node* d=NULL;
            Node* prev=start;
            while(cur!=NULL)
            {
                     d=cur->next;         
                    cur->next=start; 
                    start=cur;
                    prev->next=d;


                   cur=d;

            }
     }
     void sortBubble()
     {
        Node *i=start,*j=start,*prev=NULL,*temp=NULL,*after=NULL;
        int count=noOfNodes-1;int icount=0;
        while(i->next!=NULL)
        {
               j=start;
               after=j->next;
               icount=0;
               while(++icount!=count)
               {

                                     if((*j)>(*after))
                                     {
                                                      temp=after->next;
                                                      after->next=j;
                                                      prev->next=j->next;
                                                      j->next=temp;

                                                      prev=after;
                                                      after=j->next;

                                     }
                                     else{
                                      prev=j;
                                       j=after;
                                        after=after->next;  }          
               }
               i=i->next;
               count--;
        }
     }
      void traverse()
      {
           Node *cur=(start);
           int c=0;
           while(cur!=NULL)
           {
                     //   cout<<"start"<<start;    
                          c++;    
                          cur->print();
                          cur=cur->next;
           }
           noOfNodes=c;
      }  
      ~LList()
      {
              delete start;
      }
};

int main()
{
    int n;
    cin>>n;
    int d;
    LList list;
    Node *node;
    Node *temp=new Node(2123);
    for(int i=0;i<n;i++)
    {
            cin>>d;
            node=new Node(d);
            list.addAtLast(node);

    }

   list.addAtPos(temp,1);

    cout<<"traverse\n";
    list.traverse();
    temp=new Node(12);
    list.removeNode(temp);
    cout<<"12 removed";
    list.traverse();
    list.reverseList();
    cout<<"\nreversed\n";
    list.traverse();
    cout<<"bubble sort\n";
    list.sortBubble();
    list.traverse();
    getch();
     delete node;
    return 0;
}

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