60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
|
#include <stdlib.h>
|
||
|
|
#include "stack.h"
|
||
|
|
|
||
|
|
struct s_link {
|
||
|
|
unsigned value;
|
||
|
|
struct s_link *next;
|
||
|
|
};
|
||
|
|
|
||
|
|
typedef struct s_link link;
|
||
|
|
|
||
|
|
struct s_stack {
|
||
|
|
link *first;
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
/* crée une pile vide */
|
||
|
|
stack create_stack(void) {
|
||
|
|
return (stack) calloc(1, sizeof(struct s_stack));
|
||
|
|
}
|
||
|
|
|
||
|
|
/* ajoute un élément à la pile. Renvoie 1 en cas de succès */
|
||
|
|
int push(stack the_stack, unsigned the_value) {
|
||
|
|
link *new = (link*) malloc(sizeof(link));
|
||
|
|
if (new == NULL) {
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
new->value = the_value;
|
||
|
|
new->next = the_stack->first;
|
||
|
|
the_stack->first = new;
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* renvoie 1 si la pile est vide */
|
||
|
|
int empty(stack the_stack) {
|
||
|
|
return the_stack->first == NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* retire un élément de la pile. Renvoie l'élément retiré, ou -1 en cas d'échec */
|
||
|
|
long pop(stack the_stack) {
|
||
|
|
if(the_stack->first == NULL) {
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
link l = *(the_stack->first);
|
||
|
|
free(the_stack->first);
|
||
|
|
the_stack->first = l.next;
|
||
|
|
return l.value;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* détruit une pile en libérant les ressources associées */
|
||
|
|
void destroy_stack(stack the_stack) {
|
||
|
|
link *current, *saved;
|
||
|
|
|
||
|
|
current = the_stack->first;
|
||
|
|
while(current != NULL) {
|
||
|
|
saved = current->next;
|
||
|
|
free(current);
|
||
|
|
current = saved;
|
||
|
|
}
|
||
|
|
free(the_stack);
|
||
|
|
}
|