Homework New

Exercise/Homework3/二叉树查找结点及父结点.cpp

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+#include <iostream>
+#include <vector>
+#include<string>
+#include <sstream>
+using namespace std;
+
+template <class T>
+struct Node {
+    T element;
+    Node<T>* left;
+    Node<T>* right;
+    Node<T>* parent;
+
+    Node(const T& e, Node<T>* p) : element(e), parent(p), left(nullptr), right(nullptr) {}
+};
+
+template <class T>
+class BinTree {
+public:
+    Node<T>* root;
+    int height;
+    vector<T> arr;
+
+    BinTree() : root(nullptr), height(0) {}
+    BinTree(const vector<T>& arrs) : arr(arrs), height(0) {}
+    void test() {
+        for (auto x : arr) {
+            cout << x << " ";
+        }
+    }
+    Node<T>* returnroot() {
+        return this->root;
+    }
+
+    Node<T>* build(int& index, Node<T>* parent) {
+        if (index >= arr.size() || arr[index] == 0) {
+            index++;
+            return nullptr;
+        }
+
+        Node<T>* node = new Node<T>(arr[index], parent);
+        index++;
+        node->left = build(index, node);
+        node->right = build(index, node);
+
+        return node;
+    }
+
+    void buildTree() {
+        int index = 0;
+        this->root = build(index, nullptr);
+    }
+
+    //<2F><><EFBFBD><EFBFBD>
+    void preorder(Node<T>* node) {
+        if (node == nullptr) return;
+
+        cout << node->element << " ";
+        preorder(node->left);
+        preorder(node->right);
+    }
+    void inorder(Node<T>* node) {
+        if (node == nullptr) return;
+
+        inorder(node->left);
+        cout << node->element << ", parent";
+        //cout << ( node->parent == nullptr ? 0 : node->parent->element) << endl;
+        inorder(node->right);
+    }
+    void postorder(Node<T>* node) {
+        if (node == nullptr) return;
+
+        postorder(node->left);
+        postorder(node->right);
+        cout << node->element << " ";
+    }
+    Node<T>* inorder2(Node<T>* node, const T& x) {
+        if (node == nullptr) return nullptr;
+
+        if (node->element == x) {
+            return node;
+        }
+
+        Node<T>* leftResult = inorder2(node->left, x);
+        if (leftResult != nullptr) {
+            return leftResult;
+        }
+
+        Node<T>* rightResult = inorder2(node->right, x);
+        return rightResult;
+    }
+    void findparent(const T& e) {
+        auto x = inorder2(this->root, e);
+        if (x == nullptr || x->parent == nullptr) cout << 0 << endl;
+        else         cout << x->parent->element << endl;
+    }
+};
+
+int main() {
+    int x = 0;
+    vector<int> arr;
+    string line;
+    getline(cin, line);
+    stringstream ss(line);
+    int num;
+
+    while (ss >> num) {
+        arr.push_back(num);
+    }
+    BinTree<int> tree(arr);
+    tree.buildTree();
+
+    int m;
+    cin >> m;
+    for (int i = 0; i < m; i++) {
+        int t;
+        cin >> t;
+        tree.findparent(t);
+    }
+    return 0;
+}