C++ 代码

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:

    // Encodes a tree to a single string.
    string serialize(TreeNode* root) {
        string res;
        if(!root) return res;
        queue<TreeNode*> lo;
        lo.push(root);
        while(!lo.empty())
        {
            auto node = lo.front();
            lo.pop();
            if(!node)
            {
                res+="#,";
            }
            else
            {
                res += (to_string(node->val) + ',');//res.push_back(',');
                lo.push(node->left),lo.push(node->right);
            }
        }
        return res;
    }

    // Decodes your encoded data to tree.
    TreeNode* deserialize(string str) {
        if(str.length() == 0 ) return nullptr;
        string rootval = str.substr(0,str.find_first_of(','));
        auto root = new TreeNode(stoi(rootval));
        str = str.substr(str.find_first_of(',')+1);
        queue<TreeNode*> tree;
        tree.push(root);
        while(!tree.empty() && !str.empty())
        {
            auto node = tree.front();
            tree.pop();
            if(str[0] == '#')
            {
                node->left = nullptr;
                str = str.substr(str.find_first_of(',')+1);
            }
            else
            {
                int v = stoi(str.substr(0,str.find_first_of(',')));
                node->left = new TreeNode(v);
                tree.push(node->left);
                str = str.substr(str.find_first_of(',')+1);
            }
            if(str[0] == '#')
            {
                node->right = nullptr;
                str = str.substr(str.find_first_of(',')+1);
            }
            else
            {
                int v = stoi(str.substr(0,str.find_first_of(',')));
                node->right = new TreeNode(v);
                tree.push(node->right);
                str = str.substr(str.find_first_of(',')+1);
            }
        }

        return root;
    }
};