84 lines
1.5 KiB
C
84 lines
1.5 KiB
C
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// Пример реализации очереди при помощи однонаправленного списка
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#include <stdio.h>
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#include <stdlib.h>
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typedef int datatype;
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typedef struct list
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{
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datatype value;
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struct list *next;
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} queue;
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_Bool empty_queue(queue *p)
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{
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return p == NULL;
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}
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datatype dequeue(queue **p)
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{
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queue *ptmp = *p;
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datatype c;
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if (empty_queue(*p))
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{ // Попытка взять из пустой очереди
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fprintf(stderr, "Error. Queue is empty\n");
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exit(1);
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}
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c = ptmp->value;
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*p = ptmp->next;
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free(ptmp);
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return c;
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}
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void enqueue(struct list **pl, datatype data)
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{
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struct list *ptmp = *pl,
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*elem;
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elem = malloc(sizeof(struct list));
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elem->value = data;
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elem->next = NULL;
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if (*pl == NULL)
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{
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*pl = elem;
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return;
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}
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while (ptmp->next)
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ptmp = ptmp->next;
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ptmp->next = elem;
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}
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void enqueue_recurs(struct list **pl, datatype data)
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{
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if (*pl == NULL)
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{
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(*pl) = malloc(sizeof(struct list));
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(*pl)->value = data;
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(*pl)->next = NULL;
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return;
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}
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else
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{
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enqueue_recurs(&((*pl)->next), data);
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}
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}
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void print_list(struct list *pl)
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{
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while (pl)
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{
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printf("%d ", pl->value);
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pl = pl->next;
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}
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printf("\n");
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}
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int main()
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{
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queue *pq = NULL;
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for (int i = 1; i <= 5; i++)
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enqueue_recurs(&pq, i);
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for (int i = 1; i <= 5; i++)
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printf("%d\n", dequeue(&pq));
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return 0;
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}
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