[剑指Offer] 61.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 == NULL)
        {
            return "#";
        }
        string cur_val = to_string(root->val);
        cur_val += '!';
        char* left = Serialize(root->left);
        char* right = Serialize(root->right);
        char* ret = new char[strlen(left) + strlen(right) + cur_val.size()];
        strcpy(ret, cur_val.c_str());
        strcat(ret, left);
        strcat(ret, right);
        return ret;
    }
    TreeNode* Deserialize(char* str)
    {
        return Decode(str);
    }
    TreeNode* Decode(char*& str)
    {
        if (*str == '#')
        {
            str ++;
            return NULL;
        }
        string val;
        while (*str != '!')
        {
            val += *str;
            ++str;
        }
        TreeNode* new_node = new TreeNode(stoi(val));
        ++str;
        new_node->left = Decode(str);
        new_node->right = Decode(str);

        return new_node;
    }
};