カスタム両端キュー（両端キュー）クラス。

Question

これは.ThisコードC++でカスタム両端キュー（両端キュー）クラスを構築する私の最初の時間は、頭とtail.Whatは、私が何をすべきために私に複数の定義のエラーを与えているのですか？どのような変更を行う必要がありますか？

//これはヘッダーファイル（dequeue.h）である

 #ifndef DEQUEUE_H 
#define DEQUEUE_H 
#include <iostream> 
#include <cstdlib> 

using namespace std; 
/* 
* Node Declaration 
*/ 
struct node 
{ 
    int info; 
    node *next; 
    node *prev; 

}*head, *tail; 

class dequeue 
{ 
    public: 
     int top1, top2; 
     void insert(); 
     void del(); 
     void display(); 
     dequeue() 
     { 
      top1 = 0; 
      top2 = 0; 
      head = NULL; 
      tail = NULL; 
     } 
}; 

#endif // DEQUEUE_H 

//これはdequeue.cppファイル

#include "dequeue.h" 
#include <iostream> 

using namespace std; 


/* 
* Insert Element in Doubly Ended Queue 
*/ 
void dequeue::insert() 
{ 
    struct node *temp; 
    int ch, value; 
    if (top1 + top2 >= 50) 
    { 
     cout<<"Dequeue Overflow"<<endl; 
     return; 
    } 
    if (top1 + top2 == 0) 
    { 
     cout<<"Enter the value to be inserted: "; 
     cin>>value; 
     head = new (struct node); 
     head->info = value; 
     head->next = NULL; 
     head->prev = NULL; 
     tail = head; 
     top1++; 
     cout<<"Element Inserted into empty deque"<<endl; 
    } 
    else 
    { 
     while (1) 
     { 
      cout<<endl; 
      cout<<"1.Insert Element at first"<<endl; 
      cout<<"2.Insert Element at last"<<endl; 
      cout<<"3.Exit"<<endl; 
      cout<<endl; 
      cout<<"Enter Your Choice: "; 
      cin>>ch; 
      cout<<endl; 
      switch(ch) 
      { 
      case 1: 
       cout<<"Enter the value to be inserted: "; 
       cin>>value; 
       temp = new (struct node); 
       temp->info = value; 
       temp->next = head; 
       temp->prev = NULL; 
       head->prev = temp; 
       head = temp; 
       top1++; 
       break; 
      case 2: 
       cout<<"Enter the value to be inserted: "; 
       cin>>value; 
       temp = new (struct node); 
       temp->info = value; 
       temp->next = NULL; 
       temp->prev = tail; 
       tail->next = temp; 
       tail = temp; 
       top2++; 
       break; 
      case 3: 
       return; 
       break; 
      default: 
       cout<<"Wrong Choice"<<endl; 
      } 
     } 
    } 
} 

/* 
* Delete Element in Doubly Ended Queue 
*/ 
void dequeue::del() 
{ 
    if (top1 + top2 <= 0) 
    { 
     cout<<"Deque Underflow"<<endl; 
     return; 
    } 
    int ch; 
    while (1) 
    { 
     cout<<endl; 
     cout<<"1.Delete Element at first"<<endl; 
     cout<<"2.Delete Element at last"<<endl; 
     cout<<"3.Exit"<<endl; 
     cout<<endl; 
     cout<<"Enter Your Choice: "; 
     cin>>ch; 
     cout<<endl; 
     switch(ch) 
     { 
     case 1: 
      head = head->next; 
      head->prev = NULL; 
      top1--; 
      break; 
     case 2: 
      tail = tail->prev; 
      tail->next = NULL; 
      top2--; 
      break; 
     case 3: 
      return; 
      break; 
     default: 
      cout<<"Wrong Choice"<<endl; 
     } 
    } 
} 

/* 
* Display Doubly Ended Queue 
*/ 
void dequeue::display() 
{ 
    struct node *temp; 
    int ch; 
    if (top1 + top2 <= 0) 
    { 
     cout<<"Deque Underflow"<<endl; 
     return; 
    } 
    while (1) 
    { 
     cout<<endl; 
     cout<<"1.Display Deque from Beginning"<<endl; 
     cout<<"2.Display Deque from End"<<endl; 
     cout<<"3.Exit"<<endl; 
     cout<<endl; 
     cout<<"Enter Your Choice: "; 
     cin>>ch; 
     cout<<endl; 
     switch (ch) 
     { 
     case 1: 
      temp = head; 
      cout<<"Deque from Beginning:"<<endl; 
      while (temp != NULL) 
      { 
       cout<<temp->info<<" "; 
       temp = temp->next; 
      } 
      cout<<endl; 
      break; 
     case 2: 
      cout<<"Deque from End:"<<endl; 
      temp = tail; 
      while (temp != NULL) 
      { 
       cout<<temp->info<<" "; 
       temp = temp->prev; 
      } 
      temp = tail; 
      cout<<endl; 
      break; 
     case 3: 
      return; 
      break; 
     default: 
      cout<<"Wrong Choice"<<endl; 
     } 
    } 
} 

//これはmain.cpp`位

を含みます

#include "dequeue.h" 

using namespace std; 

int main() 
{ 
    int choice; 
    dequeue dl; 
    while (1) 
    { 
     cout<<"\n-------------"<<endl; 
     cout<<"Operations on Deque"<<endl; 
     cout<<"\n-------------"<<endl; 
     cout<<"1.Insert Element into the Deque"<<endl; 
     cout<<"2.Delete Element from the Deque"<<endl; 
     cout<<"3.Traverse the Deque"<<endl; 
     cout<<"4.Quit"<<endl; 
     cout<<"Enter your Choice: "; 
     cin>>choice; 
     cout<<endl; 
     switch(choice) 
     { 
     case 1: 
      dl.insert(); 
      break; 
     case 2: 
      dl.del(); 
      break; 
     case 3: 
      dl.display(); 
      break; 
     case 4: 
      exit(1); 
      break; 
     default: 
      cout<<"Wrong Choice"<<endl; 
     } 
    } 
    return 0; 
} 

` 

Answer 1

headおよびtailの変数は、dequeue.hファイルを含むすべての場所で定義されます。彼らはdequeueのクラスのメンバーになるために、あなたは

を意味しましたか？

あなたは本当に、それらを共有するのcppファイルに移動し、Hファイルでそれらをextern宣言する場合。