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43 lines
1.2 KiB
C++
43 lines
1.2 KiB
C++
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/**
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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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/* 層序走訪 */
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vector<int> levelOrder(TreeNode *root) {
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// 初始化佇列，加入根節點
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queue<TreeNode *> queue;
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queue.push(root);
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// 初始化一個串列，用於儲存走訪序列
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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(); // 隊列出隊
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vec.push_back(node->val); // 儲存節點值
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if (node->left != nullptr)
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queue.push(node->left); // 左子節點入列
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if (node->right != nullptr)
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queue.push(node->right); // 右子節點入列
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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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/* 初始化二元樹 */
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// 這裡藉助了一個從陣列直接生成二元樹的函式
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TreeNode *root = vectorToTree(vector<int>{1, 2, 3, 4, 5, 6, 7});
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cout << endl << "初始化二元樹\n" << endl;
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printTree(root);
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/* 層序走訪 */
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vector<int> vec = levelOrder(root);
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cout << endl << "層序走訪的節點列印序列 = ";
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printVector(vec);
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return 0;
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}
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