Leetcode#106 Construct Binary Tree from Inorder and Postorder Traversal

原题地址

 

二叉树基本操作

[       ]O[              ]

[       ][              ]O

 

代码：

 1 TreeNode *restore(vector<int> &inorder, vector<int> &postorder, int ip, int pp, int len) {

 2   if (len == 0)

 3     return NULL;

 4 

 5   TreeNode *node = new TreeNode(postorder[pp + len - 1]);

 6 

 7   if (len == 1)

 8     return node;

 9 

10   int leftLen = 0;

11   while (inorder[ip + leftLen] != postorder[pp + len - 1])

12     leftLen++;

13   node->left = restore(inorder, postorder, ip, pp, leftLen);

14   node->right = restore(inorder, postorder, ip + leftLen + 1, pp + leftLen, len - leftLen - 1);

15 

16   return node;

17 }

18 

19 TreeNode *buildTree(vector<int> &inorder, vector<int> &postorder) {

20   return restore(inorder, postorder, 0, 0, inorder.size());

21 }