Follow up for problem "Populating Next Right Pointers in Each Node".
What if the given tree could be any binary tree? Would your previous solution still work?
Note:
- You may only use constant extra space.
For example,
Given the following binary tree,
1 / 2 3 / 4 5 7
After calling your function, the tree should look like:
1 -> NULL / 2 -> 3 -> NULL / 4-> 5 -> 7 -> NULL
/** * Definition for binary tree with next pointer. * struct TreeLinkNode { * int val; * TreeLinkNode *left, *right, *next; * TreeLinkNode(int x) : val(x), left(NULL), right(NULL), next(NULL) {} * }; */ class Solution { public: void connect(TreeLinkNode *root) { if(root==NULL)return; if(root->left) { if(root->right)root->left->next=root->right; else { TreeLinkNode *tmp=root->next; while(tmp&&root->left->next==NULL) { if(tmp->left)root->left->next=tmp->left; else if(tmp->right)root->left->next=tmp->right; else tmp=tmp->next; } } } if(root->right) { TreeLinkNode *tmp=root->next; while(tmp&&root->right->next==NULL) { if(tmp->left)root->right->next=tmp->left; else if(tmp->right)root->right->next=tmp->right; else tmp=tmp->next; } } connect(root->right); connect(root->left); } };