题目描述
思路
一招层序历遍走遍天下。
解答
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
vector<int> largestValues(TreeNode* root) {
vector<int> res;
if(!root) return res;
queue<TreeNode*> q;
q.push(root);
while(!q.empty())
{
auto size = q.size();
int cur = q.front()->val;
while(size--)
{
TreeNode* temp = q.front();
q.pop(); //一开始忘记写这句,导致内存溢出
if(temp->val > cur) cur = temp->val;
if(temp->left) q.push(temp->left);
if(temp->right) q.push(temp->right);
}
res.push_back(cur);
}
return res;
}
};