cours_progra/bac2/os/chap2/ex6.c
2023-10-24 20:25:22 +02:00

54 lines
927 B
C

#include <stdlib.h>
#include <stdio.h>
typedef struct node{
void* data;
struct node* next;
} NODE;
//Could be only head but it allows a complexity of O(1) instead of O(n) for insertion (where n would be the size of the chain)
typedef struct {
NODE* head;
NODE* tail;
} FIFO;
FIFO mkfifo ();
void enqueue(FIFO *lst ,void* el);
void* dequeue(FIFO *lst);
int main(void)
{
int a = 5;
int b = 12;
FIFO fifo = mkfifo();
enqueue(&fifo, &a);
enqueue(&fifo, &b);
int *c = dequeue(&fifo);
int *d = dequeue(&fifo);
printf("%d\n", *c);
printf("%d\n", *d);
}
FIFO mkfifo (){
return (FIFO) {NULL, NULL};
}
void enqueue(FIFO *lst ,void *el){
NODE *new = calloc(1, sizeof(NODE));
new->data = el;
if(lst->tail != NULL)
lst->tail->next = new;
lst->tail = new;
lst->head = lst->head == NULL ? new : lst->head;
}
void* dequeue(FIFO *lst){
void* ret = lst->head->data;
lst->head = lst->head->next;
return ret;
}