Given a binary tree
struct TreeLinkNode {
TreeLinkNode *left;
TreeLinkNode *right;
TreeLinkNode *next;
}
Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL.
Initially, all next pointers are set to NULL.
Note:
For example,
Given the following perfect binary tree,
1
/ 2 3
/ \ / 4 5 6 7
After calling your function, the tree should look like:
1 -> NULL
/ 2 -> 3 -> NULL
/ \ / 4->5->6->7 -> NULL
给定一个二叉树，把同层的节点连接起来。
/**
* 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 [116],布布扣,bubuko.com
LeetCode: Populating Next Right Pointers in Each Node [116]
原文地址：http://blog.csdn.net/harryhuang1990/article/details/28588215
