Careercup - Microsoft面试题 - 5672369481842688

2014-05-12 06:27

题目链接

原题：

Find the max height of a binary tree.

题目：计算二叉树的最大高度。

解法：最大高度？高度不就是最深的叶子节点到根节点的路径长度吗？我就当是高度吧，递归解决。

代码：

 // http://www.careercup.com/question?id=5672369481842688
 #include <algorithm>
 #include <iostream>
 #include <sstream>
 #include <string>
 using namespace std;

 struct TreeNode {
     int val;
     TreeNode *left;
     TreeNode *right;
     TreeNode(int _val = ): val(_val), left(nullptr), right(nullptr) {};
 };

 int height(TreeNode *root)
 {
     return root ?  + max(height(root->left), height(root->right)) : ;
 }

 void constructBinaryTree(TreeNode *&root)
 {
     static int val;
     static string str;
     static stringstream sio;

     if (cin >> str && str != "#") {
         sio << str;
         sio >> val;
         root = new TreeNode(val);
         constructBinaryTree(root->left);
         constructBinaryTree(root->right);
     } else {
         root = nullptr;
     }
 }

 void deleteTree(TreeNode *&root)
 {
     if (root == nullptr) {
         return;
     } else {
         deleteTree(root->left);
         deleteTree(root->right);
         delete root;
         root = nullptr;
     }
 }

 int main()
 {
     TreeNode *root;

     while (true) {
         constructBinaryTree(root);
         if (root == nullptr) {
             break;
         }
         cout << height(root) << endl;
         deleteTree(root);
     }

     return ;
 }