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;
queue<TreeLinkNode*> use;
use.push(root);
while(!use.empty())
{
int s = use.size();
for(int i=0; i<s; i++)
{
TreeLinkNode* t = use.front();
use.pop();
if(i == s-1)
t->next = NULL;
else
t->next = use.front();
if(t->left != NULL)
use.push(t->left);
if(t->right != NULL)
use.push(t->right);
}
}
}
};