Queue Data Structure

queue.c

#include <stdio.h>
#define Q_MAX 10

struct Queue {
 
       int queue[Q_MAX];
       int rear, 
           front; 
};

typedef struct Queue Queue;

void Queue_Init(Queue *Q) {

     Q->rear = Q->front = -1;  
};

void enQueue(Queue *Q, int value) {

     //check if the Queue is full;
     if(Q->rear == Q_MAX - 1) {

        fprintf(stderr, "%s", "Error: The Queue is full!");
    
     } else {
 
            if(Q->front == -1) Q->front = 0;

            Q->queue[++Q->rear] = value;  

     }
}

int deQueue(Queue *Q) {


     if(Q->front == -1) {

        fprintf(stderr, "%s", "Error: The Queue is empty!");
  
     } else {

        int tmp = Q->queue[Q->front];

        Q->front++;

        if(Q->front > Q->rear) Q->front = Q->rear = -1;

        printf("deleted: %d\n", tmp);    

        return tmp;     
     }    
}

int main(int argc, char *argv[]) {

    Queue Q;
  
    Queue_Init(&Q);
 
    enQueue(&Q, 198);
    enQueue(&Q, 90); 
    enQueue(&Q, 32);

    deQueue(&Q); 
    deQueue(&Q);
    deQueue(&Q);
    deQueue(&Q);    
return(0);
}