Data Structures using C++

  #include < iostream.h > 
  #include < conio.h > 
  #include < stdlib.h > 
  struct node 
   { 
     char name[20]; 
     int age; 
     float height; 
     node *nxt; 
   }; 
  node *start_ptr=NULL; 
  int main() 
  { 
     void push (); 
     void pop(); 
     char ch; 
     clrscr(); 
     cout<<"Queue"; 
     cout<<"-----"; 
     do 
     { 
       cout<<"Select an operation"; 
       cout<<"u->push"; 
       cout<<"o->pop"; 
       cout<<"e->exit"; 
       cin>>ch; 
       switch(ch) 
       { 
         case 'u': 
           push(); 
           break; 
         case 'o': 
           pop(); 
           break; 
         case 'e': 
           exit(0); 
       } 
     }while(ch!='e'); 
     return 0; 
  } 
  void pop() 
  { 
     node *temp1,*temp2; 
     if(start_ptr==NULL) 
       cout<<"The list is empty"; 
     else 
     { 
       temp1=start_ptr; 
       temp2=temp1; 
       while(temp1->nxt!=NULL) 
       { 
         temp2=temp1; 
         temp1=temp1->nxt; 
       } 
       if(temp1==temp2) 
       { 
         cout<< temp1->name<<","; 
         cout<< temp1->age<<", "; 
         cout<< temp1->height; 
         start_ptr=NULL; 
       } 
       else 
       { 
         cout<< temp1->name<<", "; 
         cout<< temp1->age<<", "; 
         cout<< temp1->height; 
         temp2->nxt=NULL; 
         delete temp1; 
       } 
     } 
  } 
  void push () 
   { 
     node *temp; 
     temp = new node; 
     cout << "Please enter the name of the person: "; 
     cin >> temp->name; 
     cout << "Please enter the age of the person: "; 
     cin >> temp->age; 
     cout << "Please enter the height of the person: "; 
     cin >> temp->height; 
     if (start_ptr == NULL) 
     { 
       temp->nxt=NULL; 
       start_ptr = temp; 
     } 
     else 
     { 
       temp->nxt=start_ptr; 
       start_ptr=temp; 
     } 
   }