Java实现查找二叉树&C++的做法
写了个Java的查找二叉树，用递归做的，不用递归的还没弄出来。先贴一下。回头再研究。
BTreeTest.java:
public class BTreeTest{ class Node{ Node left, right; int data; Node(int newData){ left = null; right = null; data = newData; } } Node root = null; int count = 0; boolean canFind = false; public void insert(int data){ root = insert(root, data); } private Node insert(Node node, int data){ if(node == null){ node = new Node(data); }else if(data <= node.data){ node.left = insert(node.left, data); }else{ node.right = insert(node.right, data); } return node; } public void preOrder(){ preOrder(root); } private void preOrder(Node node){ if(node != null){ System.out.print(node.data + ","); preOrder(node.left); preOrder(node.right); } } public void inOrder(){ inOrder(root); } private void inOrder(Node node){ if(node != null){ inOrder(node.left); System.out.print(node.data + ","); inOrder(node.right); } } public void postOrder(){ postOrder(root); } private void postOrder(Node node){ if(node != null){ postOrder(node.left); postOrder(node.right); System.out.print(node.data + ","); } } public boolean search(int data){ search(data, root); return canFind; } private void search(int data, Node node) { if(node != null){ if(data == node.data){ canFind = true; }else if(data < node.data){ count++; search(data, node.left); }else if(data > node.data){ count++; search(data, node.right); } } } public void showCount(){ System.out.print("Count times: " + count); } public static void main(String[] args){ BTreeTest tree = new BTreeTest(); int a[] = {6,5,7,1,9,8,10}; for(int i=0; i< 7; i++){ //printf("%d", a[i]); System.out.println("Insert data=" + a[i]); tree.insert(a[i]); } System.out.print("先序\n"); tree.preOrder(); System.out.print("\n中序\n"); tree.inOrder(); System.out.print("\n后序\n"); tree.postOrder(); int value = 4; if(tree.search(value)){ System.out.println("Can find " + value); }else{ System.out.println("Cannot find " + value); } tree.showCount(); } }/** out put: ****** Insert data=6 Insert data=5 Insert data=7 Insert data=1 Insert data=9 Insert data=8 Insert data=10 前序: 6,5,1,7,9,8,10, 中序 1,5,6,7,8,9,10, 后序 1,5,8,10,9,7,6, 层次 6,5,7,1,9,8,10, 14 is not in the tree,search for 4 */
参考了C++实现的代码：http://www.cppblog.com/emptysoul/archive/2008/11/24/67747.html，其实以上的代码基本就是看了之后敲成Java代码...
转帖一下：
BTree.h:
#ifndef BTREE_H #define BTREE_H #include <iostream> #include <queue> using namespace std; static int findcounts; //用于测试查找某节点的次数 template<class T> class BTree { //定义树节点，包括一个数据，两个指针 struct BNode { BNode(T dat, BNode* l, BNode* r) : data(dat), left(l), right(r){}; T data; BNode *left, *right; }* root; //插入一个节点， void Insert(const T& data, BNode*& p) { if(p == 0) { p = new BNode(data, 0, 0); std::cout << "Insert data=" << data << std::endl; } else if(data < p->data) { //插入数据小于父节点数据，插入左子树 Insert(data, p->left); } else if(data > p->data) { //插入数据小于父节点数据，插入右子树 Insert(data, p->right); } } //先序遍历 void PreOrder (BNode* p) { if(p != 0) { Print(p); PreOrder (p->left); PreOrder (p->right); } } //中序遍历 void InOrder (BNode* p) { if(p != 0) { InOrder (p->left); Print(p); InOrder (p->right); } } //后序遍历 void PostOrder (BNode* p) { if(p != 0) { PostOrder (p->left); PostOrder (p->right); Print(p); } } //查找节点 bool Find(const T& data, BNode* p) { if(p != 0) { if(data == p->data) { return true; } else if(data < p->data) { findcounts ++; Find(data, p->left); } else { findcounts ++; Find(data, p->right); } } else { return false; } } //删除整棵树 void MakeEmpty(BNode* p) { if(p != 0) { MakeEmpty(p->left); MakeEmpty(p->right); std::cout << "del " << p->data << ","; delete p; } } public: BTree() : root(0){} ~BTree() { MakeEmpty(root); } void Insert(const T& data) { Insert(data, root); } void PreOrder() { //递归，前序遍历 PreOrder(root); } void InOrder() { //递归，中序遍历 InOrder(root); } void PostOrder() { //递归，后序遍历 PostOrder(root); } //层次遍历，使用队列的特性实现树的非递归遍历 void LevelOrder () { queue<BNode*> q; BNode* p = root; while(p) { Print(p); if(p->left != 0) { q.push(p->left); } if(p->right != 0) { q.push(p->right); } if (q.empty()) { break; } p = q.front(); q.pop(); } } //打印一个节点值 void Print(BNode* p) { if(p != 0) { std::cout << p->data << ","; } } //打印一个节点的查找次数 void PrintStatic() { std::cout << findcounts; } //递归查找一个节点 bool Find(const T& data) { findcounts = 0; return Find(data, root); } }; #endif
Test.cpp:
#include <iostream> #include <cstdlib> #include <ctime> #include <stdio.h> #include "BTree.h" using namespace std; int main(int argc, char *argv[]) { //随机生成一棵树 BTree<int> tree; srand((unsigned)time(NULL)); //for(int i=0; i<20; ++i) // { // int var = rand() / 20; // printf("%d", var); // tree.Insert(var); // } int a[7] = {6,5,7,1,9,8,10}; for(int i=0; i< 7; i++){ //printf("%d", a[i]); tree.Insert(a[i]); } cout << "前序:" << endl; tree.PreOrder(); cout << endl; cout << "中序" << endl; tree.InOrder(); cout << endl; cout << "后序" << endl; tree.PostOrder(); cout << endl; cout << "层次" << endl; tree.LevelOrder(); cout << endl; if(tree.Find(6)) { cout << "6 is in the tree,search for " ; tree.PrintStatic(); cout << endl; } else { cout << "14 is not in the tree,search for " ; tree.PrintStatic(); cout << endl; } system("PAUSE"); //return 0; } /** out put: ****** Insert data=6 Insert data=5 Insert data=7 Insert data=1 Insert data=9 Insert data=8 Insert data=10 前序: 6,5,1,7,9,8,10, 中序 1,5,6,7,8,9,10, 后序 1,5,8,10,9,7,6, 层次 6,5,7,1,9,8,10, 14 is not in the tree,search for 4 */
