From 682fb98c41eda7d51a183ffe5305af1e2ff41d76 Mon Sep 17 00:00:00 2001
From: Orestis <orestis.malaspinas@pm.me>
Date: Mon, 16 Dec 2024 14:33:51 +0100
Subject: [PATCH] added queue
---
slides/exemples/queue.c | 109 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 109 insertions(+)
create mode 100644 slides/exemples/queue.c
diff --git a/slides/exemples/queue.c b/slides/exemples/queue.c
new file mode 100644
index 0000000..f6f2d54
--- /dev/null
+++ b/slides/exemples/queue.c
@@ -0,0 +1,109 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <assert.h>
+
+struct element {
+ int data;
+ struct element *next;
+};
+
+struct queue {
+ struct element *head;
+ struct element *tail;
+};
+
+void queue_init(struct queue *fa) {
+ fa->head = NULL;
+ fa->tail = NULL;
+}
+
+bool queue_is_empty(struct queue fa) {
+ return (fa.head == NULL && fa.tail == NULL);
+}
+
+int queue_tail(struct queue fa) {
+ assert(!queue_is_empty(fa) && "Careful the queue is empty.");
+ return fa.tail->data;
+}
+int queue_head(struct queue fa) {
+ assert(!queue_is_empty(fa) && "Careful the queue is empty.");
+ return fa.head->data;
+}
+
+void queue_enqueue(struct queue *fa, int val) {
+ struct element *elem = malloc(sizeof(*elem));
+ elem->data = val;
+ elem->next = NULL;
+ if (queue_is_empty(*fa)) {
+ fa->tail = elem;
+ fa->head = elem;
+ } else {
+ fa->tail->next = elem;
+ fa->tail = elem;
+ }
+}
+
+int queue_dequeue(struct queue *fa) {
+ if (queue_is_empty(*fa)) {
+ assert(false && "Empty queue, impossible to dequeue.");
+ // do something
+ return -1;
+ } else if (fa->head != fa->tail) {
+ struct element *tmp_elem = fa->head; // 1
+ int tmp_val = fa->head->data; // 2
+ fa->head = fa->head->next; // 3
+ free(tmp_elem); // 4
+ return tmp_val; // 5
+ } else {
+ struct element *tmp_elem = fa->head; // 1
+ int tmp_val = fa->head->data; // 2
+ fa->head = NULL; // 3
+ fa->tail = NULL; // 3
+ free(tmp_elem); // 4
+ return tmp_val; // 5
+ }
+}
+
+void queue_destroy(struct queue *fa) {
+ while (!queue_is_empty(*fa)) {
+ queue_dequeue(fa);
+ }
+}
+
+int main() {
+ struct queue fa; // mémoire est allouée
+ queue_init(&fa);
+ printf("is fa empty? %s\n", queue_is_empty(fa) ? "yes" : "no");
+
+ printf("enqueuing 10\n");
+ queue_enqueue(&fa, 10);
+ printf("enqueuing 20\n");
+ queue_enqueue(&fa, 20);
+ printf("enqueuing 30\n");
+ queue_enqueue(&fa, 30);
+ printf("is fa empty? %s\n", queue_is_empty(fa) ? "yes" : "no");
+
+ int v1 = queue_dequeue(&fa);
+ printf("v1 contains? %d\n", v1);
+ printf("head contains? %d\n", queue_head(fa));
+ printf("tail contains? %d\n", queue_tail(fa));
+ int v2 = queue_dequeue(&fa);
+ int v3 = queue_dequeue(&fa);
+ printf("v2 contains? %d\n", v2);
+ printf("v3 contains? %d\n", v3);
+ printf("is fa empty? %s\n", queue_is_empty(fa) ? "yes" : "no");
+
+ printf("enqueuing 10\n");
+ queue_enqueue(&fa, 10);
+ printf("enqueuing 20\n");
+ queue_enqueue(&fa, 20);
+ printf("enqueuing 30\n");
+ queue_enqueue(&fa, 30);
+ printf("is fa empty? %s\n", queue_is_empty(fa) ? "yes" : "no");
+ printf("destroying\n");
+ queue_destroy(&fa);
+ printf("is fa empty? %s\n", queue_is_empty(fa) ? "yes" : "no");
+
+ return EXIT_SUCCESS;
+}
--
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