https://leetcode.com/problems/flatten-binary-tree-to-linked-list/
Given a binary tree,flatten it to a linked list in-place.
For example,given the following tree:
1 / 2 5 / \ 3 4 6
The flattened tree should look like:
1 2 3 4 5 6
代码:
/** * 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 flatten(TreeNode* root) { if(!root) return; flatten(root -> left); flatten(root -> right); TreeNode* R = root -> right; root -> right = root -> left; root -> left = NULL; TreeNode* cur = root; while(cur -> right) cur = cur -> right; cur -> right = R; } };
好像一个世纪那么久没写 LC 了