Cds programs queue and circular queue

Implementation of Queue using arrays
#include
#include
#include
int r=-1,f=-1,j,n,*queue,element,ch;
void display();
void insert();
int del();
int main()
{

clrscr();
printf(“\n enter the size of the queue”);
scanf(“%d”,&n);
queue=(int*)malloc(n*2);
while(1)
{
printf(“\n enter ur choice\n 1.insert \n 2.display \n 3.delete \n 4.exit”);
scanf(“%d”,&ch);
switch(ch)
{
case 1:insert();break;
case 2:
printf(“\n Elements of queue are:”);
display();
break;
case 3:element=del();
printf(“the element deleted is %d”,element);
break;
default: exit(0);
}
}
getch();
return 0;
}
void display()
{
for(r=0;r=n)
{
printf(“overflow”);
break;
}

else
{
printf(“enter a no to insert”);
scanf(“%d”,&element);
queue[++r]=element;
}
}
}
int del()
{
if(f==r)
{
printf(“the queue is empty”);
return 0;
}
f++;
element=queue[f];
if(f==n)
{
f=1;
r=1;
}
return element;
}

Implementation of circular queue

#include
#include
#include
int r=-1,f=-1,j,n,*queue,element,ch;
void display();
void insert();
int del();
int main()
{

clrscr();
printf(“\n enter the size of the queue”);
scanf(“%d”,&n);
queue=(int*)malloc(n*2);
while(1)
{
printf(“\n enter ur choice\n 1.insert \n 2.display \n 3.delete \n 4.exit”);
scanf(“%d”,&ch);
switch(ch)
{
case 1:insert();break;
case 2:
printf(“\n Elements of queue are:”);
display();
break;
case 3:element=del();
printf(“the element deleted is %d”,element);
break;
default: exit(0);
}
}
getch();
return 0;
}
void display()
{
for(r=0;r
printf(“%d”,queue[r]);
}

void insert()
{
while(1)
{
if((r==n-1))
{
printf(“overflow”);
break;
}
printf(“enter a no to insert”);
scanf(“%d”,&element);
queue[++r]=element;

if(f==r)
f=0;

}
}
int del()
{
if(f==n)
f=0;
if(f==r)
{
printf(“the queue is empty”);
return 0;
}
f++;
element=queue[f];
return element;
}