Leetcode 297. Serialize and Deserialize Binary Tree
Leetcode 297. Serialize and Deserialize Binary Tree
Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.
Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.
For example, you may serialize the following tree
1
/ \
2 3
/ \
4 5
as "[1,2,3,null,null,4,5]", just the same as how LeetCode OJ serializes a binary tree. You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.
Note: Do not use class member/global/static variables to store states. Your serialize and deserialize algorithms should be stateless.
二叉树的序列化与反序列化。
其实就是通过某一种遍历方法将树变成序列存储，再将序列还原成树。用一个非数字的字符表示空节点，比如“#”
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Codec {
public:
void dfs(string &path, TreeNode* root)
{
if(!root)
{
path += "#";
return ;
}
path += to_string(root->val) + "#";
dfs(path, root->left);
dfs(path, root->right);
}
// Encodes a tree to a single string.
string serialize(TreeNode* root) {
string res;
dfs(res, root);
return res;
}
TreeNode* dfs2(string &data)
{
int pos = data.find("#");
if(!pos)
{
data = data.substr(pos + 1);
return NULL;
}
TreeNode* root = new TreeNode(stoi(data.substr(0, pos)));
data = data.substr(pos + 1);
root->left = dfs2(data);
root->right = dfs2(data);
return root;
}
// Decodes your encoded data to tree.
TreeNode* deserialize(string data) {
string data2 = data;
return dfs2(data2);
}
};
// Your Codec object will be instantiated and called as such:
// Codec codec;
// codec.deserialize(codec.serialize(root)); 腾讯云开发者
