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:
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
给定一棵二叉树，要求每层上的节点链接起来。
/**
* 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;
TreeLinkNode*prev;
TreeLinkNode*cur;
queue<TreeLinkNode*>q1;
queue<TreeLinkNode*>q2;
q1.push(root);
while(!q1.empty() || !q2.empty()){
prev=NULL;
if(!q1.empty()){
while(!q1.empty()){
cur=q1.front(); q1.pop();
if(prev)prev->next=cur;
prev=cur;
//把下层节点保存到q2
if(cur->left)q2.push(cur->left);
if(cur->right)q2.push(cur->right);
}
cur->next=NULL;
}
else{
while(!q2.empty()){
cur=q2.front(); q2.pop();
if(prev)prev->next=cur;
prev=cur;
//把下层节点保存到q1
if(cur->left)q1.push(cur->left);
if(cur->right)q1.push(cur->right);
}
cur->next=NULL;
}
}
}
};LeetCode: Populating Next Right Pointers in Each Node II [117],布布扣,bubuko.com
LeetCode: Populating Next Right Pointers in Each Node II [117]
原文地址：http://blog.csdn.net/harryhuang1990/article/details/28849661
