[Update] Add find_min/max_node + test

tests/test.c

@@ -154,6 +154,44 @@ static MunitResult test_tree_search()
   return MUNIT_OK;
 }
 
+static MunitResult test_tree_find_max_node()
+{
+  node_t* nd = bst_create();
+  munit_assert_true(bst_is_empty(nd));
+  nd = bst_insert(nd,12);
+  nd = bst_insert(nd,22);
+  nd = bst_insert(nd,32);
+  nd = bst_insert(nd,42);
+  nd = bst_insert(nd,2);
+  nd = bst_insert(nd,3);
+  nd = bst_insert(nd,4);
+  nd = bst_insert(nd,5);
+  nd = bst_insert(nd,10);
+  nd = bst_insert(nd,50);
+  munit_assert_int32(bst_find_max_node(nd)->val,==,50);
+  bst_destroy(nd);
+  return MUNIT_OK;
+}
+
+static MunitResult test_tree_find_min_node()
+{
+  node_t* nd = bst_create();
+  munit_assert_true(bst_is_empty(nd));
+  nd = bst_insert(nd,12);
+  nd = bst_insert(nd,22);
+  nd = bst_insert(nd,32);
+  nd = bst_insert(nd,42);
+  nd = bst_insert(nd,2);
+  nd = bst_insert(nd,3);
+  nd = bst_insert(nd,4);
+  nd = bst_insert(nd,5);
+  nd = bst_insert(nd,10);
+  nd = bst_insert(nd,50);
+  munit_assert_int32(bst_find_min_node(nd)->val,==,2);
+  bst_destroy(nd);
+  return MUNIT_OK;
+}
+
 static MunitResult test_tree_is_BST()
 {
   node_t* nd = bst_create();
@@ -234,6 +272,14 @@ static MunitTest test_suite_tests[] = {
     MUNIT_TEST_OPTION_NONE,
     NULL
   },
+  {
+    (char*) "/test_tree_find_min_node",
+    test_tree_find_min_node,
+    NULL,
+    NULL,
+    MUNIT_TEST_OPTION_NONE,
+    NULL
+  },
   {
     (char*) "/test_tree_find_max",
     test_tree_find_max,
@@ -242,6 +288,14 @@ static MunitTest test_suite_tests[] = {
     MUNIT_TEST_OPTION_NONE,
     NULL
   },
+  {
+    (char*) "/test_tree_find_max_node",
+    test_tree_find_max_node,
+    NULL,
+    NULL,
+    MUNIT_TEST_OPTION_NONE,
+    NULL
+  },
   {
     (char*) "/test_tree_search",
     test_tree_search,

tree.c

@@ -33,36 +33,49 @@ bool bst_is_bst(node_t *tree)
     }
 }
 
-
-int bst_find_min(node_t *tree)
+node_t *bst_find_min_node(node_t *tree)
 {
-    if(tree == NULL)
+    node_t* tmp = tree;
+    if(tmp == NULL)
     {
-        return INT_MIN;
+        return NULL;
     }
-    if(tree->left != NULL)
+    if(tmp->left != NULL)
     {
-        return bst_find_min(tree->left);
+        return bst_find_min_node(tmp->left);
     }
     else
     {
-        return tree->val;
+        return tmp;
     }
 }
 
+int bst_find_min(node_t *tree)
+{
+    node_t* tmp = bst_find_min_node(tree);
+    return (tmp != NULL)?tmp->val:INT_MIN;
+}
+
 int bst_find_max(node_t *tree)
 {
-    if(tree == NULL)
+    node_t* tmp = bst_find_max_node(tree);
+    return (tmp != NULL)?tmp->val:INT_MAX;
+}
+
+node_t* bst_find_max_node(node_t *tree)
 {
-        return INT_MIN;
+    node_t* tmp = tree;
+    if(tmp == NULL)
+    {
+        return NULL;
     }
-    if(tree->right != NULL)
+    if(tmp->right != NULL)
     {
-        return bst_find_max(tree->right);
+        return bst_find_max_node(tmp->right);
     }
     else
     {
-        return tree->val;
+        return tmp;
     }
 }