From 755eedde3ff12dad82c5a4cff0b6d9611150e630 Mon Sep 17 00:00:00 2001
From: jussi <jussi.kuokkanen@protonmail.com>
Date: Wed, 6 Nov 2019 23:17:28 +0200
Subject: [PATCH] lib: add binary search tree implementation

---
 src/include/tc_common.h | 19 +++++++++++++++
 src/lib/tc_common.c     | 53 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/src/include/tc_common.h b/src/include/tc_common.h
index 2621153..504f809 100644
--- a/src/include/tc_common.h
+++ b/src/include/tc_common.h
@@ -15,7 +15,9 @@ extern "C" {
 
 // Tagged union of data types for simulating function overloading
 enum tc_data_types {
+    TC_TYPE_NONE,
     TC_TYPE_INT,
+    TC_TYPE_UINT,
     TC_TYPE_DOUBLE,
     TC_TYPE_STRING,
     TC_TYPE_STRING_ARR
@@ -25,6 +27,7 @@ typedef struct {
     enum tc_data_types data_type;
     union {
         int64_t int_value;
+        uint64_t uint_value;
         double double_value;
         char *string_value;
     };
@@ -44,6 +47,22 @@ char **tc_str_arr_dup(uint16_t str_count, char **const strings);
 // Deallocate string array
 void tc_str_arr_free(uint16_t str_count, char **strings);
 
+// Binary search tree whose left node contains the smaller value
+typedef struct tc_bin_node_ {
+    void *key;
+    void *value;
+    
+    struct tc_bin_node_ *left;
+    struct tc_bin_node_ *right;
+} tc_bin_node_t;
+
+// Create a new node with key and data in the appropriate position
+tc_bin_node_t *tc_bin_node_insert(tc_bin_node_t* node, void *key, void *value);
+// Find the value associated with the key
+void *tc_bin_node_find_value(tc_bin_node_t *node, void *key);
+// Destroy a node and its children
+void tc_bin_node_destroy(tc_bin_node_t *node);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/lib/tc_common.c b/src/lib/tc_common.c
index 1fc5cab..22a8b2f 100644
--- a/src/lib/tc_common.c
+++ b/src/lib/tc_common.c
@@ -18,3 +18,56 @@ void tc_str_arr_free(uint16_t str_count, char **strings) {
     }
     free(strings);
 }
+
+static tc_bin_node_t *new_bin_node(void *key, void *value) {
+    tc_bin_node_t *new_node = calloc(1, sizeof(tc_bin_node_t));
+    new_node->key = key;
+    new_node->value = value;
+    return new_node;
+}
+
+static void single_destroy(tc_bin_node_t *node) {
+    free(node);
+}
+
+static void traverse_postorder(tc_bin_node_t *node, void (*func)(tc_bin_node_t*)) {
+    if (node->left) {
+        traverse_postorder(node, func);
+    }
+    if (node->right) {
+        traverse_postorder(node, func);
+    }
+    func(node);
+}
+
+tc_bin_node_t *tc_bin_node_insert(tc_bin_node_t *node, void *key, void *value) {
+    if (node == NULL) {
+        return new_bin_node(key, value);
+    }
+    
+    if (key < node->key) {
+        node->left = tc_bin_node_insert(node->left, key, value);
+    }
+    else if (key > node->key) {
+        node->right = tc_bin_node_insert(node->right, key, value);
+    }
+    return node;
+}
+
+void *tc_bin_node_find_value(tc_bin_node_t *node, void *key) {
+    if (node == NULL) {
+        return NULL;
+    }
+    if (node->key == key) {
+        return node->value;
+    }
+    
+    if (node->key < key) {
+        return tc_bin_node_find_value(node->right, key);
+    }
+    return tc_bin_node_find_value(node->left, key);
+}
+
+void tc_bin_node_destroy(tc_bin_node_t *node) {
+    traverse_postorder(node, &single_destroy);
+}