10_5.cpp

本文档是C＋＋程序设计教程系列的部分辅助代码。

//10_5

#include <iostream.h>

struct Lnode
{
  double data;
  Lnode* next;
};

void ShowList(const Lnode* const head);
void DeleteList(Lnode* head);
void AddToEnd(Lnode* pnew, Lnode*& head);
Lnode* GetNode();
Lnode* Merge(Lnode* h1, Lnode* h2);
void Insert(Lnode*& head, Lnode* p);

void main()
{
  Lnode* head1=NULL;
  Lnode* temp;
  double d;
  cout <<"data? ";
  cin >>d;
  while(d>0&&(temp=GetNode())){
    temp->data=d;
    AddToEnd(temp, head1);
    cout <<"data? ";
    cin >>d;
  }
  ShowList(head1);

  Lnode* head2=NULL;
  cout <<"data? ";
  cin >>d;
  while(d>0&&(temp=GetNode())){
    temp->data=d;
    AddToEnd(temp, head2);
    cout <<"data? ";
    cin >>d;
  }
  ShowList(head2);

  Lnode* head = Merge(head1,head2);

  ShowList(head);
  DeleteList(head);
}

void ShowList(const Lnode* const head)
{
  for(Lnode* p=(Lnode*)head; p; p=p->next)
    cout <<p->data <<"  ";
  cout <<endl;
}

void DeleteList(Lnode* head)
{
  for(Lnode* p=head; p; ){
    Lnode* t=p;
    p=p->next;
    delete t;
  }
}

Lnode* Merge(Lnode* h1, Lnode* h2)
{
  Lnode* newHead = h1;
  for(Lnode* p=h2; p; ){
    Lnode* t=p;
    p=p->next;
    Insert(newHead,t);
  }
  return newHead;
}

void Insert(Lnode*& head, Lnode* p)
{
  if(!head){
    head = p;
    p->next = NULL;
    return;
  }
  if(head->data > p->data){
    p->next = head;
    head =p;
    return;
  }
  Lnode* sp;
  for(sp=head; sp->next&& sp->next->data < p->data; sp=sp->next);
  p->next = sp->next;
  sp->next = p;
}

void AddToEnd(Lnode* pnew, Lnode*& head)
{
  if(!head)
    head=pnew;
  else{
    Lnode* p;
    for(p=head; p->next; p=p->next);
    p->next = pnew;
  }
  pnew->next=NULL;
}

Lnode* GetNode()
{
  Lnode* item = new Lnode;
  if(item){
    item->next=NULL;
    item->data=0.0;
  }else
    cout <<"Nothing allocated\n";
  return item;
}