Queue in C

Working of queue on the basis of first-in-first-out (FIFO) data structure. Here we discuss about Queue in C

Queue real life of example

A real-world example of queue can be a single-lane one-way road, where the vehicle enters first, exits first. More real-world examples can be seen as queues at the ticket windows and bus-stops.

Example of Queue in C

#include<conio.h>
#include<stdio.h>
#define N 6
int queue[N]={0};
int rear=0,front=0;
void insert(void);
void del(void);
void disp(void);
void cre(void);
void main()
{
int user=0;
clrscr();
while(user!=4)
{
clrscr();
printf("\n\n\n\t\t\t Size of Queue is %d",N);
printf("\n\t 1.INSERT");
printf("\n\t 2.DELETE");
printf("\n\t 3.DISPLAY");
printf("\n\t 4.EXIT");
printf("\n\t 5.CREATE");
scanf("%d",&user);
switch(user)
{
case 1:
insert();
break;
case 2:
del();
break;
case 3:
disp();
break;
case 4:
printf("\n\t Thank You");
break;
case 5:
cre();
break;
}
getch();
}
getch();
}

/**************Insert value in Queue************/
void insert(void)
{
int t;
if(rear<N)
{
printf("\n\t Enter value in Queue");
scanf("%d",&t);
queue[rear]=t;
rear++;
}
else
{
printf("\n\t Q Overflow!!!!!!!!!!!!!!!");
}
}
void del(void)
{
int i;
printf("\n\t %d gets deleted.........",queue[front]);
queue[front]=0;
front++;
}
void disp(void)
{
int i;
for(i=front;i<rear;i++)
{
printf("\n\t %d",queue[i]);
}
}
void cre(void)
{
int t;
printf("\n\t Enter a value in Queue");
scanf("%d",&t);
front=0;
queue[front]=t;
rear=front+1;
}