后序与中序得原二叉树，与上篇类似。

/** * 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 *buildTree(vector
     
       &inorder, vector
      
        &postorder) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        return build(inorder,postorder,inorder.size(),0,postorder.size()-1);    }    TreeNode* build(vector
       
         &inorder,vector
        
          &postorder,int size,int i,int p)    {        if(size==0)        return NULL;        TreeNode* head = (TreeNode*)malloc(sizeof(TreeNode));        head->val = postorder[p];        int j;        for(j=i;j
         
          left = build(inorder,postorder,j-i,i,p-size+(j-i));        head->right = build(inorder,postorder,size-(j-i)-1,j+1,p-1);        return head;    }};