序列化二叉树和反序列化二叉树

题目描述

请实现两个函数，分别用来序列化和反序列化二叉树

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};
*/
class Solution {
public:
    char* Serialize(TreeNode *root) {    
        if(!root) return "#";
        string str = to_string(root->val);
        str += ',';
        char* left = Serialize(root->left);
        char* right = Serialize(root->right);
        char* ret = new char[strlen(left) + strlen(right) + str.size()];
        strcpy(ret,str.c_str());
        strcat(ret,left);
        strcat(ret,right);
        return ret;
    }
    TreeNode* Deserialize(char *&str) {
        if(*str == '#'){
            ++str;
            return nullptr;
        } 
        string s;
        while(*str != ','){
            s += *str;
            ++str;
        }
        ++str;
        TreeNode* root = new TreeNode(atoi(s.c_str()));
        root->left = Deserialize(str);
        root->right = Deserialize(str);
        return root;
    }
};