tema tp 3-4

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAXMES 257
#define CHUNK 128

void checkAlloc(void *p) {
  if (p == NULL) {
    perror("");
    exit(-1);
  }
}

typedef struct {
  int id;
  char message[MAXMES];
} Info;

typedef struct {
  int front, rear, mem;
  Info *buffer;
} Queue;

Queue mkQ() {
  Queue q = {0, 0, 0, NULL};
  return q;
}

void enq(Queue *q, Info info) {
  if (q->mem == q->rear) {
    q->mem += CHUNK;
    q->buffer = realloc(q->buffer, q->mem * sizeof(Info));
    checkAlloc(q->buffer);
  }
  q->buffer[q->rear++] = info;
}

int isEmpty(Queue q) {
  return q.rear == q.front;
}

Info deq(Queue *q) {
  if (isEmpty(*q)) {
    fprintf(stderr, "empty queue!\n");
    exit(-1);
  }
  return q->buffer[q->front++];
}

void freeQ(Queue q) {
  free(q.buffer);
}

int main(void) {
  Queue q = mkQ();
  static char message[MAXMES];
  for (int id = 1; fgets(message, MAXMES, stdin); id++) {
    Info info;
    info.id = id;
    message[strlen(message) - 1] = 0;
    strcpy(info.message, message);
    enq(&q, info);
  }
  while (!isEmpty(q)) {
    Info info = deq(&q);
    printf("received \"%s\" from %d\n", info.message, info.id);
  }
  freeQ(q);
  return 0;
}