层序遍历,使用queue的模板解法
C++ 代码
/*
// Definition for a Node.
class Node {
public:
int val;
vector<Node*> children;
Node() {}
Node(int _val) {
val = _val;
}
Node(int _val, vector<Node*> _children) {
val = _val;
children = _children;
}
};
*/
class Solution {
public:
vector<vector<int>> levelOrder(Node* root) {
vector<vector<int>> res;
queue<Node*> q;
if(root)q.push(root);
while(q.size()){
int sz = q.size();
vector<int> level;
for(int i=0; i<sz; ++i) {
Node* t = q.front();
q.pop();
level.push_back(t->val);
for(auto c : t->children) {
if(c)q.push(c);
}
}
res.push_back(level);
}
return res;
}
};