LeetCode 538. Convert BST to Greater Tree
阿新 • • 發佈:2018-12-05
Given a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus sum of all keys greater than the original key in BST.
Example:
Input: The root of a Binary Search Tree like this: 5 / \ 2 13 Output: The root of a Greater Tree like this: 18 / \ 20 13
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: void inorder(TreeNode* root){ if(root==NULL) return; inorder(root->right); root->val=(temp+=root->val); inorder(root->left); } TreeNode* convertBST(TreeNode* root) { inorder(root); return root; } private: int temp=0; };