{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "https://leetcode.com/problems/subtree-of-another-tree\n",
    "\n",
    "\n",
    "\n",
    "Runtime: 28 ms, faster than 92.94% of C++ online submissions for Subtree of Another Tree.\n",
    "Memory Usage: 29.8 MB, less than 26.77% of C++ online submissions for Subtree of Another Tree.\n",
    "\n",
    "\n",
    "\n",
    "```cpp\n",
    "/**\n",
    " * Definition for a binary tree node.\n",
    " * struct TreeNode {\n",
    " *     int val;\n",
    " *     TreeNode *left;\n",
    " *     TreeNode *right;\n",
    " *     TreeNode() : val(0), left(nullptr), right(nullptr) {}\n",
    " *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}\n",
    " *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}\n",
    " * };\n",
    " */\n",
    "class Solution {\n",
    "public:\n",
    "    bool is_end(TreeNode* node) {\n",
    "        if (node != nullptr) {\n",
    "            if ((node->left == nullptr) && (node->right == nullptr)) {\n",
    "                return true;\n",
    "            } \n",
    "        }\n",
    "        return false;\n",
    "    }\n",
    "    \n",
    "    bool compare(TreeNode* a, TreeNode* b) {\n",
    "        if ((a == nullptr) && (b == nullptr)) {\n",
    "            return true;\n",
    "        } else {\n",
    "           if ((a != nullptr) && (b != nullptr)) {\n",
    "               if (a->val == b->val) {\n",
    "                   if (is_end(a) && is_end(b)) {\n",
    "                       return true;\n",
    "                   }\n",
    "                   return compare(a->left, b->left) && compare(a->right, b->right);\n",
    "               } else {\n",
    "                   return false;\n",
    "               }\n",
    "           } else {\n",
    "               return false;\n",
    "           }\n",
    "        }\n",
    "    }\n",
    "    \n",
    "    bool travel(TreeNode* node) {\n",
    "        if (node == nullptr) {\n",
    "            return false;\n",
    "        } else {\n",
    "            if (compare(node, t)) {\n",
    "                return true;\n",
    "            }\n",
    "            //printf(\"%d \", node->val);\n",
    "            return travel(node->left) || travel(node->right);\n",
    "        }\n",
    "    }\n",
    "    \n",
    "    bool isSubtree(TreeNode* s, TreeNode* t) {\n",
    "        this->t = t;\n",
    "        return travel(s);\n",
    "    }\n",
    "    \n",
    "private:\n",
    "    TreeNode* t = nullptr;\n",
    "};\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "attemps: 10\n",
    "\n",
    "spent: 2 hours"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "C++17",
   "language": "C++17",
   "name": "xcpp17"
  },
  "language_info": {
   "codemirror_mode": "text/x-c++src",
   "file_extension": ".cpp",
   "mimetype": "text/x-c++src",
   "name": "c++",
   "version": "17"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 4
}