Construct Binary Tree from Inorder and Postorder Traversal

最新推荐文章于 2021-02-03 15:56:42 发布

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最新推荐文章于 2021-02-03 15:56:42 发布

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原文链接：http://www.cnblogs.com/Kai-Xing/p/3917146.html

Given inorder and postorder traversal of a tree, construct the binary tree.

Note:
You may assume that duplicates do not exist in the tree.

 1 class Solution {
 2 public:
 3     TreeNode *buildTree(vector<int> &inorder, vector<int> &postorder) {
 4         return build_Tree(inorder.begin(), inorder.end(), postorder.begin(), postorder.end());
 5     }
 6     
 7     TreeNode *build_Tree(vector<int>::iterator in_b, vector<int>::iterator in_e, vector<int>::iterator post_b, vector<int>::iterator post_e){
 8         if(in_b == in_e || post_b == post_e) return NULL;
 9         
10         TreeNode *root = new TreeNode(*prev(post_e));
11         auto root_p = find(in_b, in_e, *prev(post_e));
12         auto tmp = next(post_b, distance(in_b, root_p));
13         
14         root->left = build_Tree(in_b, root_p, post_b, tmp);
15         root->right = build_Tree(next(root_p), in_e, tmp, prev(post_e));
16         
17         return root;
18     }
19 };