D) Queues [Array]

gistfile1.cpp

//Queue using array 
#include<iostream.h> 
#include<stdio.h> 
#include<conio.h> 
#include<stdlib.h> 
#include<ctype.h> 
  
class queue 
{ 
      public: 
             int q[5],front,rear,x,result; 
             void enterque(); 
             void deleteque(); 
             void display(); 
             queue() 
             { 
                 front=0; 
                 rear=0; 
             } 
}; 
  
void queue::enterque() 
{ 
    if(rear>=5) 
        cout<<"\n QUEUE OVERFLOW \n"; 
    else
    { 
        cout<<"\nEnter the number to be inserted: "; 
        cin>>x; 
        rear++; 
        q[rear]=x; 
        cout<<"\nNumber pushed in the queue:"<<q[rear]; 
    } 
} 
  
void queue::deleteque() 
{ 
     if(rear==0) 
     cout<<"Queue underflow"; 
     else
     { 
         if(front==rear) 
         { 
             front=0; 
             rear=0; 
         } 
         else
             front++; 
     } 
     cout<<"\nDeleted element is:"; 
     result=q[front]; 
     cout<<result; 
} 
  
void queue::display() 
{ 
     if(rear==0) 
         cout<<"\nQueue underflow\n"; 
     else
         cout<<"\nContents of queue is:"; 
         { 
             for(int i=front+1;i<=rear;i++) 
             cout<<q[i]<<"\t"; 
         } 
} 
  
int main() 
{ 
    int c; 
    queue que; 
    do
    { 
        cout<<"\n 1. Insertion\n 2. Deletion\n 3. Display\n 4. Exit "; 
        cout<<"\nEnter your choice:"; 
        cin>>c; 
        switch(c) 
        { 
            case 1: 
                 que.enterque(); 
                 break; 
            case 2: 
                 que.deleteque(); 
                 break; 
            case 3: 
                 que.display(); 
                 break; 
            case 4: 
                 exit(0); 
            default: 
                    cout<<"\nInvalid choice!!\n"; 
        } 
  
    }while(c<4); 
    getch(); 
  
}