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
Note: must process right tree first.
1 /** 2 * Definition for binary tree with next pointer. 3 * struct TreeLinkNode { 4 * int val; 5 * TreeLinkNode *left, *right, *next; 6 * TreeLinkNode(int x) : val(x), left(NULL), right(NULL), next(NULL) {} 7 * }; 8 */ 9 class Solution { 10 public: 11 void connect(TreeLinkNode *root) { 12 if (root == NULL) return; 13 14 if (root->left != NULL && root->right != NULL) root->left->next = root->right; 15 16 TreeLinkNode* cur = root->right != NULL ? root->right : root->left; 17 18 if (cur != NULL) 19 { 20 TreeLinkNode* next = root->next; 21 22 while (next != NULL) 23 { 24 if (next->left != NULL) 25 { 26 cur->next = next->left; 27 break; 28 } 29 30 if (next->right != NULL) 31 { 32 cur->next = next->right; 33 break; 34 } 35 36 next = next->next; 37 } 38 } 39 40 connect(root->right); 41 connect(root->left); 42 } 43 };