fork download
copy 
  1. #include <stdio.h>
  2. #include <stdlib.h>
  3.  
  4. #define QUEUE_SIZE 10
  5.  
  6. typedef struct {
  7.   int data[QUEUE_SIZE];
  8.   int number;
  9.   int head;
  10. } QUEUE;
  11.  
  12. QUEUE* create_queue() {
  13.   QUEUE* queue = (QUEUE*)malloc(sizeof(QUEUE));
  14.  
  15.   queue->head = 0;
  16.   queue->number = 0;
  17.   return queue;
  18. }
  19.  
  20. int enqueue(QUEUE* queue, int value) {
  21.   if (queue->head + queue->number < QUEUE_SIZE){
  22.     queue->data[queue->head + queue->number] = value;
  23.     queue->number++;
  24.     return 0;
  25.   } else { 
  26.     return -1;
  27.   }
  28. }
  29.  
  30. int dequeue(QUEUE* queue) {
  31.   int r;
  32.   if (queue->number > 0) {
  33.     r = queue->data[queue->head];
  34.     queue->head++;
  35.     queue->number--;
  36.   } else {
  37.     r = -1;
  38.   }
  39.   return r;
  40. }
  41.  
  42. int main() {
  43.   QUEUE *q = create_queue();
  44.   enqueue(q, 3);
  45.   enqueue(q, 2);
  46.   enqueue(q, 1);
  47.   printf(":%d\n", dequeue(q));
  48.   printf(":%d\n", dequeue(q));
  49.   enqueue(q, 5);
  50.   enqueue(q, 4);
  51.   printf(":%d\n", dequeue(q));
  52.   printf(":%d\n", dequeue(q));
  53.   printf(":%d\n", dequeue(q));
  54.   printf(":%d\n", dequeue(q));
  55.   free(q);
  56.   return 0;
  57. }
  58. /* end */
  59.  
  60.  
Success #stdin #stdout 0s 4420KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
:3
:2
:1
:5
:4
:-1
https://ideone.com/m5Nk7y
language:
C (gcc 8.3)
created:
7 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!