prick_btree

Still need to make it better imo

prick_btree.h

@@ -0,0 +1,149 @@
+/* prick_btree.h: A generic ordered binary tree.
+ * Created: 2025-04-09
+ * Author: Aryadev Chavali
+ * License: See end of file
+ * Commentary:
+
+ To utilise this library, please put:
+    #define PRICK_BTREE_IMPL
+    #include "prick_btree.h"
+ in one of your code units.
+
+ An ordered binary tree implementation, allowing the use of custom comparators
+ and allocators.
+ */
+
+#ifndef PRICK_BTREE_H
+#define PRICK_BTREE_H
+
+#include <stdio.h>
+
+typedef struct BNode
+{
+  void *value;
+  struct BNode *left, *right;
+} bnode_t;
+
+typedef int (*bnode_comp_fn)(void *, void *);
+typedef bnode_t *(*bnode_allocator_fn)();
+typedef void (*bnode_free_fn)(bnode_t *);
+
+bnode_t *bnode_insert(bnode_t *node, void *value, bnode_comp_fn comparator,
+                      bnode_allocator_fn allocator);
+void bnode_free(bnode_t *btree, bnode_free_fn);
+void bnode_right_rotate(bnode_t **node);
+void bnode_left_rotate(bnode_t **node);
+void bnode_print(FILE *fp, bnode_t *root);
+
+#ifdef PRICK_BTREE_IMPL
+
+#include <stdlib.h>
+
+bnode_t *bnode_insert(bnode_t *node, void *value, bnode_comp_fn comparator,
+                      bnode_allocator_fn allocator)
+{
+  if (!node)
+  {
+    node        = allocator();
+    node->value = value;
+    node->left  = NULL;
+    node->right = NULL;
+    return node;
+  }
+
+  int comp              = comparator(value, node->value);
+  bnode_t **picked_node = NULL;
+  if (comp < 0)
+    picked_node = &node->left;
+  else
+    picked_node = &node->right;
+
+  if (*picked_node)
+    bnode_insert(*picked_node, value, comparator, allocator);
+  else
+  {
+    *picked_node          = allocator();
+    picked_node[0]->value = value;
+    picked_node[0]->left  = NULL;
+    picked_node[0]->right = NULL;
+  }
+
+  return node;
+}
+
+void bnode_free(bnode_t *bnode, bnode_free_fn free_fn)
+{
+  if (!bnode)
+    return;
+  bnode_t *left  = bnode->left;
+  bnode_t *right = bnode->right;
+
+  free_fn(bnode);
+  bnode_free(left, free_fn);
+  bnode_free(right, free_fn);
+}
+
+void bnode_right_rotate(bnode_t **node)
+{
+  if (!node || !*node)
+    return;
+
+  bnode_t *left = (*node)->left;
+  if (left)
+  {
+    (*node)->left = left->right;
+    left->right   = *node;
+    *node         = left;
+  }
+}
+
+void bnode_left_rotate(bnode_t **node)
+{
+  if (!node || !*node)
+    return;
+
+  bnode_t *right = (*node)->right;
+  if (right)
+  {
+    (*node)->right = right->left;
+    right->left    = *node;
+    *node          = right;
+  }
+}
+
+void bnode_print(FILE *fp, bnode_t *root)
+{
+  if (!root)
+    return;
+  fprintf(fp, "(%p", root->value);
+  if (root->left)
+  {
+    fprintf(fp, " ");
+    bnode_print(fp, root->left);
+  }
+
+  if (root->right)
+  {
+    fprintf(fp, " ");
+    bnode_print(fp, root->right);
+  }
+
+  fprintf(fp, ")");
+}
+
+#endif
+
+#endif
+
+/* Copyright (C) 2025 Aryadev Chavali
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the Unlicense
+ * for details.
+
+ * You may distribute and modify this code under the terms of the
+ * Unlicense, which you should have received a copy of along with this
+ * program.  If not, please go to <https://unlicense.org/>.
+
+*/