From ac55496d881e0a17b3eff85f1faae5aafbc53b50 Mon Sep 17 00:00:00 2001
From: Thomas Schmucker <ts@its1.de>
Date: Wed, 22 Jul 2020 17:30:45 +0200
Subject: erster Commit

---
 queue.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 queue.c

(limited to 'queue.c')

diff --git a/queue.c b/queue.c
new file mode 100644
index 0000000..fdacca5
--- /dev/null
+++ b/queue.c
@@ -0,0 +1,86 @@
+/* Standard C */
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+/* Project */
+#include "util.h"
+
+typedef int T;
+
+struct queue_item {
+	struct queue_item *next;
+	T data;
+};
+
+struct queue {
+	struct queue_item *head, *tail;
+};
+
+void
+queue_init(struct queue *queue)
+{
+	queue->head = NULL;
+}
+
+void
+queue_put(struct queue *queue, T data)
+{
+	struct queue_item *new_item;
+
+	if ( (new_item = malloc(sizeof(*new_item))) != NULL ) {
+		struct queue_item *tmp = queue->tail;
+		new_item->data = data;
+		queue->tail = new_item;
+		if ( queue->head == NULL )
+			queue->head = queue->tail;
+		else
+			tmp->next = queue->tail;
+	}
+	else
+		ERROR("out of memory");
+}
+
+bool
+queue_get(struct queue *queue, T *data)
+{
+	if ( queue->head != NULL ) {
+		struct queue_item *next = queue->head->next;
+		*data = queue->head->data;
+		free(queue->head);
+		queue->head = next;
+
+		return true;
+	}
+	else
+		return false;
+}
+
+bool
+queue_empty(struct queue *queue)
+{
+	return queue->head == NULL;
+}
+
+int
+main()
+{
+	struct queue queue[1];
+
+	queue_init(queue);
+
+	for ( int i = 0; i != 10; ++i )
+		queue_put(queue, i);
+
+	while ( !queue_empty(queue) ) {
+		int i;
+		if ( queue_get(queue, &i) )
+			printf("%d\n", i);
+		else
+			ERROR("this shouldn't happen!");
+	}
+	return EXIT_SUCCESS;
+}
+
+
+
-- 
cgit v1.3