Careercup - Google面试题 - 5765091433644032

2014-05-08 09:32

题目链接

原题：

Given a binary tree, how would you copy it from one machine to the other, assume you have a flash drive. I believe we should write the binary tree to file and have the other machine de-serialize it. But how should we do it?

题目：如何序列化和反序列化一颗二叉树。

解法：做法当然有很多种，但基本都是基于某种遍历方式去进行文本或者二进制的表示。文本比较直观，不过二进制的序列化应该在空间上更有效率。我的思路是前序遍历，并用一个特殊符号来标记空指针。用括号来表示一颗完整的树，这样就能递归进行序列化/反序列化了。好像之前刚做了个一样的题，所以这题没有写代码。

代码：

 1 // http://www.careercup.com/question?id=5765091433644032

 2 // Transfer a binary tree to another machine? Of course, serialization and deserialization.

 3 // Any kind of tree traversal with the help of a special notation to represent 'NULL' can do the serialization.

 4 // For example, preorder traversal for the tree below:

 5 //               1

 6 //             /   \

 7 //            2     8

 8 //           / \   / \

 9 //          7  12 34  9

10 //

11 // If we use '#' to represent NULL, the preorder traversal looks like {1, 2, 7, #, #, 12, #, #, 8, 34, #, #, 9, #, #}

12 // With this you can output the array to a text file.

13 // The '#' notation ensures that every binary tree has its unique preorder traversal.

14 int main()

15 {

16     return 0;

17 }