Introduce to Queue and Array Implementation of Queue

Queue is a data structure which works based on the principle first in - first out (FIFO)

queue.h

void enqueue(int *q,int *tail, int element);
int dequeue(int *q,int *head);
int full(int tail,const int size);
int empty(int head,int tail);
void init(int *head, int *tail);

queue.c

/*initialize queue pointer*/
void init(int *head, int *tail)
{
     *head = *tail = 0;
}
/* enqueue an element	
   precondition: the queue is not full
*/
void enqueue(int *q,int *tail, int element)
{	
    q[(*tail)++] = element;
}
/* dequeue an element
   precondition: queue is not empty*/
int dequeue(int *q,int *head)
{	
     return q[(*head)++];
}
/* report queue is full nor not 
   return 1 if queue is full, otherwise return 0*/
int full(int tail,const int size)
{
    return tail == size ? 1 : 0;
}

/* report queue is empty or not	
  return 1 if the queue is empty, otherwise return 0*/
int empty(int head, int tail)
{	
     return head == tail ? 1 : 0;
}

testqueue.c

#include <stdio.h>
#include <stdlib.h>
#include "queue.h"
#define size 3
void main(){	
    int head,tail,element;	
    int queue[size];	
    // initialize queue
    init(&head,&tail);		
   // enqueue elements	
   while(full(tail,size) != 1){		
      element = rand();		
      printf("enqueue element 
%d\n",element);		
      enqueue(queue,&tail,element);		
      printf("head=%d,tail=%d\n",head,tail);	//press enter to enqueue more		getchar();	}	
      printf("queue is full\n");	
      // dequeue elements from 
      while(!empty(head,tail)){	   
         element = dequeue(queue,&head);
         printf("dequeue element %d \n",element);	   
         //press enter to pop more
         getchar();	
       }	
      printf("queue is empty\n");	
     getchar();}