43 lines
1.2 KiB
C++
43 lines
1.2 KiB
C++
/**
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* File: binary_tree_bfs.cpp
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* Created Time: 2022-11-25
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* Author: krahets (krahets@163.com)
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*/
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#include "../utils/common.hpp"
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/* 层序遍历 */
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vector<int> levelOrder(TreeNode *root) {
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// 初始化队列，加入根节点
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queue<TreeNode *> queue;
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queue.push(root);
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// 初始化一个列表，用于保存遍历序列
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vector<int> vec;
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while (!queue.empty()) {
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TreeNode *node = queue.front();
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queue.pop(); // 队列出队
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vec.push_back(node->val); // 保存节点值
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if (node->left != nullptr)
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queue.push(node->left); // 左子节点入队
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if (node->right != nullptr)
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queue.push(node->right); // 右子节点入队
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}
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return vec;
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}
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/* Driver Code */
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int main() {
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/* 初始化二叉树 */
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// 这里借助了一个从数组直接生成二叉树的函数
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TreeNode *root = vectorToTree(vector<int>{1, 2, 3, 4, 5, 6, 7});
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cout << endl << "初始化二叉树\n" << endl;
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printTree(root);
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/* 层序遍历 */
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vector<int> vec = levelOrder(root);
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cout << endl << "层序遍历的节点打印序列 = ";
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printVector(vec);
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return 0;
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}
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