首页 > 代码库 > Leetcode#105 Construct Binary Tree from Preorder and Inorder Traversal

Leetcode#105 Construct Binary Tree from Preorder and Inorder Traversal

原题地址

 

基本二叉树操作。

O[       ][              ]

[       ]O[              ]

 

代码:

 1 TreeNode *restore(vector<int> &preorder, vector<int> &inorder, int pp, int ip, int len) { 2   if (len <= 0) 3     return NULL; 4  5   TreeNode *node = new TreeNode(preorder[pp]); 6  7   if (len == 1) 8     return node; 9 10   int leftLen = 0;11   while (inorder[ip + leftLen] != preorder[pp])12     leftLen++;13   node->left = restore(preorder, inorder, pp + 1, ip, leftLen);14   node->right = restore(preorder, inorder, pp + leftLen + 1, ip + leftLen + 1, len - leftLen - 1);15 16   return node;17 }18 19 TreeNode *buildTree(vector<int> &preorder, vector<int> &inorder) {20     return restore(preorder, inorder, 0, 0, preorder.size());21 }

 

Leetcode#105 Construct Binary Tree from Preorder and Inorder Traversal