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70 lines
1.6 KiB
70 lines
1.6 KiB
/**
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* File: binary_tree_dfs.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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// 初始化串列，用於儲存走訪序列
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vector<int> vec;
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/* 前序走訪 */
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void preOrder(TreeNode *root) {
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if (root == nullptr)
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return;
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// 訪問優先順序：根節點 -> 左子樹 -> 右子樹
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vec.push_back(root->val);
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preOrder(root->left);
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preOrder(root->right);
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}
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/* 中序走訪 */
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void inOrder(TreeNode *root) {
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if (root == nullptr)
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return;
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// 訪問優先順序：左子樹 -> 根節點 -> 右子樹
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inOrder(root->left);
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vec.push_back(root->val);
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inOrder(root->right);
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}
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/* 後序走訪 */
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void postOrder(TreeNode *root) {
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if (root == nullptr)
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return;
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// 訪問優先順序：左子樹 -> 右子樹 -> 根節點
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postOrder(root->left);
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postOrder(root->right);
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vec.push_back(root->val);
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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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/* 前序走訪 */
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vec.clear();
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preOrder(root);
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cout << endl << "前序走訪的節點列印序列 = ";
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printVector(vec);
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/* 中序走訪 */
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vec.clear();
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inOrder(root);
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cout << endl << "中序走訪的節點列印序列 = ";
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printVector(vec);
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/* 後序走訪 */
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vec.clear();
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postOrder(root);
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cout << endl << "後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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