剑指offer——序列化二叉树

#include <iostream>
#include <vector>
using namespace std;


struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};

class Solution {
    private:
        vector<int> buf;
    public:
        void PreOrder(TreeNode* root){
            if(!root){
                buf.push_back(0xFFFFFFFF);
                return;
            }
            buf.push_back(root->val);
            this->PreOrder(root->left);
            this->PreOrder(root->right);
        }

        char* Serialize(TreeNode *root){
            buf.clear();
            PreOrder(root);
            int size = buf.size();
            int* ans = new int[size];
            for(int i = 0 ; i < size ; i++){
                ans[i] = buf[i];
            } 
            return (char*)ans;
        }

        TreeNode* PreCreate(int* &p){
            TreeNode* tree;
            if(*p == 0xFFFFFFFF){
                p++;
                return NULL;
            }
            tree = new TreeNode(*p);
            p++;
            tree->left = this->PreCreate(p);
            tree->right = this->PreCreate(p);
            return tree;
        }

        TreeNode* Deserialize(char *str) {
            int* p = (int*)str;
            return PreCreate(p);
        }
};