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

 

思路：注意将空节点的val设为0xffffffff，序列化时用前序遍历将树节点值作为char，反序列化时将字符串按前序遍历建树。

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};
*/
class Solution {
public:
    vector<int> v;
    void preOrder(TreeNode* root)
    {
        if(!root)
        {
            v.push_back(0xffffffff);
        }
        else
        {
            v.push_back(root->val);
            preOrder(root->left);
            preOrder(root->right);
        }
    }
    TreeNode* createTree(int* &p)
    {
        if(*p==0xffffffff)
        {
            p++;
            return NULL;
        }
        TreeNode* node = new TreeNode(*p);
        p++;
        node->left = createTree(p);
        node->right = createTree(p);
        return node;
    }
    char* Serialize(TreeNode *root) {    
        v.clear();
        preOrder(root);
        int len = v.size();
        int *res = new int[len];
        for(int i=0;i<len;i++)
        {
            res[i] = v[i];
        }
        return (char*)res;
    }
    TreeNode* Deserialize(char *str) {
        int *p = (int*)str;
        return createTree(p);
    }
};