1 files changed, 59 insertions, 0 deletions
diff --git a/advent-of-code/2022/lib/rbtree.h b/advent-of-code/2022/lib/rbtree.h
new file mode 100644
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--- /dev/null
+++ b/advent-of-code/2022/lib/rbtree.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2002 Niels Provos <provos@citi.umich.edu>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdlib.h>
+
+struct rbnode {
+  struct {
+    struct rbnode *rbe_left;
+    struct rbnode *rbe_right;
+    struct rbnode *rbe_parent;
+    int rbe_color;
+  } entry;
+  char content[0];
+};
+
+struct rbtree {
+  struct rbnode *rbh_root;
+  int (*cmp)(void *k1, void *k2);
+  void (*augment)(void *elm);
+};
+
+typedef struct rbnode RbNode;
+typedef struct rbtree RbTree;
+
+void rbtree_remove(struct rbtree *, void* iter);
+
+// return a iterator
+void* rbtree_insert(struct rbtree *, void *treenode);
+void* rbtree_find(struct rbtree *, void *val);
+void* rbtree_next(struct rbtree *, void* iter);
+void* rbtree_min(struct rbtree *);
+void* rbtree_max(struct rbtree *);
+void* rbtree_left(void *node);
+void* rbtree_right(void *node);
+void* rbtree_parent(void *node);
+
+void rbtree_free(struct rbtree *, void (*free_cb)(void*));