This is a Dequeue implementation using Array. Program code is easy written not very complex you can implement it in your own and see how it will work.

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/* http://native-code.blogspot.com */

#include<stdio.h>
#include<conio.h>
#define MAX 20
#define MID 10
void insertr(int a[],int x);
void insertl(int a[],int x);
int deletel(int a[]);
int deleter(int a[]);
int left,right;

void main()
{
    int a[MAX],op,x;
    left=MID;
    right=MID-1;
    for( ; ; )
    {
 printf("/* http://native-code.blogspot.com */\n");
 printf("\n\nEnter the option to start operation");
 printf("\n1.To insert leftside: ");
 printf("\n2.To insert rightside: ");
 printf("\n3.To delete from leftside: ");
 printf("\n4.To delete from rightside: ");
 printf("\n5.Exit");
 printf("\nEnter the option: ");
 scanf("%d",&op);
 switch(op)
 {
case 1:
printf("\nEnter element to insert leftside: ");
scanf("%d",&x);
insertl(a,x);
continue;
case 2:
printf("\nEnter element to insert rightside: ");
scanf("%d",&x);
insertr(a,x);
continue;
case 3:
x=deletel(a);
if(x!=-999)
printf("\nDeleted item: %d",x);
continue;
case 4:
x=deleter(a);
if(x!=-999)
printf("\nDeleted item : %d",x);
continue;
case 5:
break;
 }
    }
}

void insertr(int a[],int x)
{
++right;
if(right==MAX)
{

printf("\nQueue overflow / full");
return;
}
else
a[right]=x;
}

void insertl(int a[],int x)
{
--left;
if(left==-1)
{
 printf("\nQueue overflow / full");
 return;
}
else
a[left]=x;
}

int deletel(int a[])
{
int i;
if(left>right)
{
printf("\nQueue is empty now");
return -999;
}
else
{
 i=a[left];
 ++left;
 return i;
}
}

int deleter(int a[])
{
 int i;
 if(left>right)
 {
 printf("\nQueue is empty now");
 return -999;
 }
 else
 {
 i=a[right];
 right--;
 return i;
 }
}


/* http://native-code.blogspot.com */

Try this code in your computer for better understanding. Enjoy the code. If you have any Question you can contact us or mail us