queueusingarray.txt

#include <stdio.h>
#include <conio.h>
#include <stdlib.h>

int queue[10] ;

int front = -1;

int rear = -1 ;

void insert(int) ;
int del() ;
void display() ;

int main()
{
  int ch , i , item ;
  while (1)
  {
    printf("choose one \n1. Insert\n2. Delete \n3. Display \n4. exit \n") ;
    scanf("%d",&ch) ;
    switch(ch)
    {
      case 1 :
              printf("Enter the item\n") ;
              scanf("%d", &item) ;
              insert(item) ;
              break ;
      case 2 :
              printf("deleted item is %d \t", del()) ;
              break ;
      case 3 :
              display() ;
              break ;
      case 4 :
              exit(0) ;
    }
  }
}

void insert(int item)
{
  if(rear == 9)
  {
    printf("queue overflow \n") ;
    return ;
  }
  else if(front < 0)
  {
    front++ ;
    rear++ ;
  }
  else
  {
    rear = rear + 1 ;
  }
  queue[rear] = item ;
}

int del()
{
  int x ;
  if(front < 0)
  {
    printf("queue underflow \n");
    return 0 ;
  }
  else if(front == rear)
  {
    x = queue[front] ;
    front = -1 ;
    rear = -1 ;
    return x ;
  }
  else
  {
    x = queue[front] ;
    front = front + 1 ;
    return x ;
  }
}

void display()
{
  int i ;
  printf("queue elements are \t") ;
  for(i = front ; i <= rear ; i++)
  {
    printf("%d\t", queue[i]) ;
  }
}