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
class Solution {
public:
void connect(TreeLinkNode *root) {
while(root!=NULL)
{
TreeLinkNode* next = NULL;
TreeLinkNode* pre = NULL;
for(;root!=NULL;root=root->next) //遍历的原因是root是一个链表
{
if(next==NULL)
next = (root->left != NULL) ? root->left : root->right;
if(root->left)
{
if(pre)
pre->next = root->left;
pre = root->left;
}
if(root->right)
{
if(pre)
pre->next = root->right;
pre = root->right;
}
}
root = next;
}
}
};
