Implementation of search function in tree and application with correct

coding style

README.md

@@ -0,0 +1,4 @@
+
+#Задача по работе с бинарным деревом.
+1. Написать функцию поиска в бинарном дереве. Написать тесты. 
+2. Реализовать приложение, в котором демонтрируется печать бинарного дерева с выводом адресов левого и правого поддеревьев.

app/print_tree.cpp

@@ -0,0 +1,20 @@
+#include "search_in_tree.h"
+#include <iostream>
+
+int main() {
+  CNode* tree = create_tree_for_tests();
+
+  std::cout << std::endl << "Tree" << std::endl << std::endl;
+  print_tree(tree, 3);
+  std::cout << "" << std::endl;
+
+  std::cout << "Tree with adress" << std::endl << std::endl;
+  print_tree_with_adress(tree, 3);
+  CNode** res = find(&tree, 9);
+  *res = new CNode(9);
+  CNode* new_search = *(find(&tree, 9));
+  std::cout << std::endl <<
+    "Tree with adress after adding an element on found position"
+    << std::endl << std::endl;
+  print_tree_with_adress(tree, 3);
+}

include/search_in_tree.h

@@ -0,0 +1,16 @@
+#ifndef INCLUDE_SEARCH_IN_TREE_H_
+#define INCLUDE_SEARCH_IN_TREE_H_
+
+struct CNode {
+  int val;
+  CNode* left, *right;
+  explicit CNode(int v) { val = v; left = 0; right = 0; }
+};
+
+CNode** find(CNode** root, int v);
+void print_tree(CNode* root, int level);
+void print_tree_with_adress(CNode* root, int level);
+CNode* create_tree_for_tests();
+void PrintTree(CNode** root);
+
+#endif  // INCLUDE_SEARCH_IN_TREE_H_

src/search_in_tree.cpp

@@ -0,0 +1,53 @@
+#include <iostream>
+#include <queue>
+#include "search_in_tree.h"
+
+CNode** find(CNode** root, int v) {
+  CNode **tree = root;
+  while (*tree) {
+    if ((*tree)->val == v) {
+      return tree;
+    } else {
+      if ((*tree)->val < v) {
+        tree = &(*tree)->right;
+      } else {
+          tree = &(*tree)->left;
+      }
+    }
+  }
+  return tree;
+}
+
+void print_tree(CNode* root, int level) {
+  if (root) {
+    print_tree(root->right, level + 1);
+    for (int i = 0; i< level; i++) std::cout << "    ";
+    std::cout << root->val << std::endl;
+    print_tree(root->left, level + 1);
+  }
+}
+
+void print_tree_with_adress(CNode* root, int level) {
+  if (root) {
+    print_tree_with_adress(root->right, level + 1);
+    for (int i = 0; i< level; i++) std::cout << "       ";
+    std::cout << root->val << std::endl;
+    for (int i = 0; i< level-1; i++) std::cout << "       ";
+    std::cout << "   ";
+    std::cout << root->left << std::endl;
+    for (int i = 0; i< level-1; i++) std::cout << "       ";
+    std::cout << "   ";
+    std::cout << root->right << std::endl;
+    print_tree_with_adress(root->left, level + 1);
+  }
+}
+
+CNode* create_tree_for_tests() {
+  CNode* tree = new CNode(5);
+  tree->left = new CNode(3);
+  tree->right = new CNode(7);
+  (tree->right)->left = new CNode(6);
+  (tree->left)->left = new CNode(1);
+  (tree->left)->right = new CNode(4);
+  return tree;
+}

test/test.cpp

@@ -1,9 +1,50 @@
 #include <gtest/gtest.h>
-#include "add.h"
+#include "search_in_tree.h"
 
-TEST(Addition, CanAddTwoNumbers) {
-  EXPECT_EQ(add(2, 2), 4);
-  EXPECT_EQ(add(-2, 2), 0);
+TEST(Find, can_find_medium_element) {
+  CNode* tree = create_tree_for_tests();
+  CNode** res = (find(&tree, 3));
+  ASSERT_EQ((*res)->val, 3);
+}
+
+TEST(Find, can_find_leaf) {
+  CNode* tree = create_tree_for_tests();
+  CNode** res = (find(&tree, 4));
+  ASSERT_EQ((*res)->val, 4);
+}
+
+TEST(Find, return_correct_adress_when_dont_find) {
+  CNode* tree = create_tree_for_tests();
+  CNode** res = (find(&tree, 8));
+  CNode* null = 0;
+  ASSERT_EQ(*res, null);
+  *res = new CNode(8);
+  CNode* new_search = *(find(&tree, 8));
+  ASSERT_EQ(new_search->val, 8);
+}
+
+TEST(Find, dont_destruct_tree_when_can_find) {
+  CNode* tree = create_tree_for_tests();
+  CNode** res = (find(&tree, 1));
+
+  ASSERT_EQ(tree->val, 5);
+  ASSERT_EQ(tree->left->val, 3);
+  ASSERT_EQ(tree->right->val, 7);
+  ASSERT_EQ(tree->right->left->val, 6);
+  ASSERT_EQ(tree->left->left->val, 1);
+  ASSERT_EQ(tree->left->right->val, 4);
+}
+
+TEST(Find, dont_destruct_tree_when_cant_find) {
+  CNode* tree = create_tree_for_tests();
+  CNode** res = (find(&tree, 9));
+
+  ASSERT_EQ(tree->val, 5);
+  ASSERT_EQ(tree->left->val, 3);
+  ASSERT_EQ(tree->right->val, 7);
+  ASSERT_EQ(tree->right->left->val, 6);
+  ASSERT_EQ(tree->left->left->val, 1);
+  ASSERT_EQ(tree->left->right->val, 4);
 }
 
 int main(int ac, char* av[]) {