#include <stdio.h>    
    #define size 5  
    int deque[size];    
    int f = -1, r = -1;    
    //  insert_front function will insert the value from the front    
    void insert_front(int x)    
    {    
        if((f==0 && r==size-1) || (f==r+1))    
        {    
            printf("Overflow");    
        }    
        else if((f==-1) && (r==-1))    
        {    
            f=r=0;    
            deque[f]=x;    
        }    
        else if(f==0)    
        {    
            f=size-1;    
            deque[f]=x;    
        }    
        else    
        {    
            f=f-1;    
            deque[f]=x;    
        }    
    }    
        
    // insert_rear function will insert the value from the rear    
    void insert_rear(int x)    
    {    
        if((f==0 && r==size-1) || (f==r+1))    
        {    
            printf("Overflow");    
        }    
        else if((f==-1) && (r==-1))    
        {    
            r=0;    
            deque[r]=x;    
        }    
        else if(r==size-1)    
        {    
            r=0;    
            deque[r]=x;    
        }    
        else    
        {    
            r++;    
            deque[r]=x;    
        }    
        
    }    
        
    // display function prints all the value of deque.    
    void display()    
    {    
        int i=f;    
        printf("\nElements in a deque are: ");    
            
        while(i!=r)    
        {    
            printf("%d ",deque[i]);    
            i=(i+1)%size;    
        }    
         printf("%d",deque[r]);    
    }    
        
    // getfront function retrieves the first value of the deque.    
    void getfront()    
    {    
        if((f==-1) && (r==-1))    
        {    
            printf("Deque is empty");    
        }    
        else    
        {    
            printf("\nThe value of the element at front is: %d", deque[f]);    
        }    
            
    }    
        
    // getrear function retrieves the last value of the deque.    
    void getrear()    
    {    
        if((f==-1) && (r==-1))    
        {    
            printf("Deque is empty");    
        }    
        else    
        {    
            printf("\nThe value of the element at rear is %d", deque[r]);    
        }    
            
    }    
        
    // delete_front() function deletes the element from the front    
    void delete_front()    
    {    
        if((f==-1) && (r==-1))    
        {    
            printf("Deque is empty");    
        }    
        else if(f==r)    
        {    
            printf("\nThe deleted element is %d", deque[f]);    
            f=-1;    
            r=-1;    
                
        }    
         else if(f==(size-1))    
         {    
             printf("\nThe deleted element is %d", deque[f]);    
             f=0;    
         }    
         else    
         {    
              printf("\nThe deleted element is %d", deque[f]);    
              f=f+1;    
         }    
    }    
        
    // delete_rear() function deletes the element from the rear    
    void delete_rear()    
    {    
        if((f==-1) && (r==-1))    
        {    
            printf("Deque is empty");    
        }    
        else if(f==r)    
        {    
            printf("\nThe deleted element is %d", deque[r]);    
            f=-1;    
            r=-1;    
                
        }    
         else if(r==0)    
         {    
             printf("\nThe deleted element is %d", deque[r]);    
             r=size-1;    
         }    
         else    
         {    
              printf("\nThe deleted element is %d", deque[r]);    
              r=r-1;    
         }    
    }    
        
    int main()    
    {    
        insert_front(20);    
        insert_front(10);    
        insert_rear(30);    
        insert_rear(50);    
        insert_rear(80);    
        display();  // Calling the display function to retrieve the values of deque    
        getfront();  // Retrieve the value at front-end  
        getrear();  // Retrieve the value at rear-end   
        delete_front();    
        delete_rear();    
        display(); // calling display function to retrieve values after deletion   
        return 0;    
    }