LeetCode 116 Populating Next Right Pointers in Each Node

题目

分析

题解

/**
* 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;
vector<TreeLinkNode*> tree;
tree.push_back(root);
while(!tree.empty()){
vector<TreeLinkNode*> vec;
int i;
for(i=0;i<tree.size()-1;i++){
tree[i]->next = tree[i+1];
if(tree[i]->left != NULL)
vec.push_back(tree[i]->left);
if(tree[i]->right != NULL)
vec.push_back(tree[i]->right);
}
tree[i]->next = NULL;
if(tree[i]->left != NULL)
vec.push_back(tree[i]->left);
if(tree[i]->right != NULL)
vec.push_back(tree[i]->right);
tree = vec;
}
}
};