//

// Solution102.cpp

// Algorithm

//

// Created by Pancf on 2019/12/23.

// Copyright © 2019 Pancf. All rights reserved.

//

#include "Solution102.hpp"

#include <queue>

using std::queue;

vector<vector<int>> Solution102::levelOrder(TreeNode *root) {

vector<vector<int>> rv;

if (!root) {

return rv;

}

queue<TreeNode *> q;

q.push(root);

while (!q.empty()) {

size_t level_size = q.size();

vector<int> level_node;

for (size_t i = 0; i < level_size; ++i) {

auto top = q.front();

level_node.push_back(top->val);

if (top->left) {

q.push(top->left);

}

if (top->right) {

q.push(top->right);

}

q.pop();

}

rv.push_back(level_node);

}

return rv;

}