problem-solving-resources/queue.c at main · tanim913/problem-solving-resources · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
#include <stdio.h>
#define queue_size 100

typedef struct
{
    int data [queue_size+1];
    int head, tail;

} Queue;

void enqueue (Queue *q, int item)
{
    if(((q->tail+1) % (queue_size+1)) == q->head)
    {
        printf("Queue is full..");
        return;
    }
    q->data[q->tail] = item;
    q->tail = (q->tail+1) % (queue_size+1);
}


int dequeue (Queue *q)
{
    int item;
    if(q->tail == q->head)
    {
        printf("queue is empty\n");
        return -1;
    }

    item = q->data[q->head];
    q->head = (q->head+1) % (queue_size+1);
    return item;
}


int main ()
{

    Queue my_q;

    my_q.head = 0;
    my_q.tail = 0;

    enqueue(&my_q,50);
    printf("tail : %d\n",my_q.tail);
    enqueue(&my_q,70);
    printf("tail : %d\n",my_q.tail);
    enqueue(&my_q,90);
    printf("tail : %d\n",my_q.tail);
    enqueue(&my_q,110);
    printf("tail : %d\n",my_q.tail);

    printf("%d\n",dequeue(&my_q));
    printf("%d\n",dequeue(&my_q));
    printf("%d\n",dequeue(&my_q));
    printf("%d\n",dequeue(&my_q));
    printf("%d\n",dequeue(&my_q));

}