重建二叉树

/** * Definition for binary tree * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    TreeNode* reConstructBinaryTree(vector<int> pre,vector<int> vin) {        if(pre.size()==0)return NULL;        TreeNode* node=new TreeNode(pre[0]);        int p=0;        for(p=0;p<pre.size();p++)            {            if(vin[p]==pre[0])break;        }        vector<int> pre_left,pre_right,vin_left,vin_right;        for(int i=0;i<pre.size();i++)            {            if(i<p)                {                pre_left.push_back(pre[i+1]);                vin_left.push_back(vin[i]);            }            else if(i>p){                pre_right.push_back(pre[i]);                vin_right.push_back(vin[i]);                           }        }        node->left=reConstructBinaryTree(pre_left,vin_left);        node->right=reConstructBinaryTree(pre_right,vin_right);        return node;    }};