From e04525e6f7802be30481477b272e39c55230db83 Mon Sep 17 00:00:00 2001
From: Thomas Schmucker <ts@its1.de>
Date: Sun, 20 Sep 2026 10:41:37 +0200
Subject: initial import

---
 main.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 main.c

(limited to 'main.c')

diff --git a/main.c b/main.c
new file mode 100644
index 0000000..a176f89
--- /dev/null
+++ b/main.c
@@ -0,0 +1,141 @@
+// Standard C
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// RB-Implementierung
+#include <sys/tree.h>
+
+// clang-format off
+struct address {
+	char name[41];
+	int  age;
+
+	RB_ENTRY(address) links;
+};
+// clang-format on
+
+// type: struct address_tree { ... };
+RB_HEAD(address_tree, address);
+
+int
+address_compare(const struct address *lhs, const struct address *rhs)
+{
+	int res;
+
+	if ( (res = strcmp(lhs->name, rhs->name)) != 0 )
+		return res;
+
+	return (lhs->age < rhs->age) ? -1 : (lhs->age > rhs->age);
+}
+
+void
+address_init(struct address *address, const char *name, int age)
+{
+	strlcpy(address->name, name, sizeof(address->name));
+	address->age = age;
+}
+
+struct address *
+address_new(const char *name, int age)
+{
+	struct address *address;
+
+	if ( (address = malloc(sizeof *address)) != NULL ) {
+		address_init(address, name, age);
+	}
+	return address;
+}
+
+// Prototypen
+RB_PROTOTYPE_STATIC(address_tree, address, links, address_compare)
+
+// Implemtierungen
+RB_GENERATE_STATIC(address_tree, address, links, address_compare)
+
+void
+insert(struct address_tree *addresses, struct address *address)
+{
+	RB_INSERT(address_tree, addresses, address);
+}
+
+void
+iterate(struct address_tree *addresses)
+{
+	struct address *ptr;
+	for ( ptr = RB_MIN(address_tree, addresses);
+	      ptr != NULL;
+	      ptr = RB_NEXT(address_tree, addresses, ptr) ) {
+		printf("%s\n", ptr->name);
+	}
+}
+
+void
+iterate2(struct address_tree *addresses)
+{
+	struct address *ptr;
+	RB_FOREACH(ptr, address_tree, addresses)
+	{
+		printf("%s\n", ptr->name);
+	}
+}
+
+struct address *
+search(struct address_tree *addresses, const char *name, int age)
+{
+	struct address key;
+
+	address_init(&key, name, age);
+
+	return RB_FIND(address_tree, addresses, &key);
+}
+
+void
+delete_one(struct address_tree *addresses, struct address *address)
+{
+	if ( address != NULL ) {
+		RB_REMOVE(address_tree, addresses, address);
+		free(address);
+	}
+}
+
+void
+delete_all(struct address_tree *addresses)
+{
+	struct address *ptr;
+	while ( (ptr = RB_MIN(address_tree, addresses)) != NULL ) {
+		RB_REMOVE(address_tree, addresses, ptr);
+		free(ptr);
+	}
+}
+
+int
+main(void)
+{
+	struct address_tree addresses = RB_INITIALIZER(&addresses);
+
+	// struct address_tree addresses;
+	// RB_INIT(&addresses);
+
+	insert(&addresses, address_new("Thomas", 44));
+	insert(&addresses, address_new("Markus", 44));
+	insert(&addresses, address_new("Miriam", 44));
+	insert(&addresses, address_new("Albert", 44));
+
+	iterate(&addresses);
+
+	struct address *ptr_miriam = search(&addresses, "Miriam", 44);
+
+	if ( ptr_miriam != NULL )
+		printf("Gefunden: %s (%d)\n", ptr_miriam->name, ptr_miriam->age);
+	else
+		printf("Nicht gefunden\n");
+
+	delete_one(&addresses, ptr_miriam);
+
+	iterate2(&addresses);
+
+	delete_all(&addresses);
+
+	return EXIT_SUCCESS;
+}
-- 
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