广义表法建立二叉树

一直以来对树稍微存在一点儿恐惧感，最近打算好好顺一顺数据结构，于是从二叉树开始对树进行研究。这个方法主要参考殷人昆第二版的数据结构（清华大学出版社第二版）。实现也都是用模板，后来的实例是用char型。其中涉及到友员函数和操作符重载的使用，这一块有点儿忘了，就当复习了一下。

/*********************************date:2014.5.10author:andrew**********************************///BinTree.h#include<iostream>using namespace std;template<class T>//definition of the node of binary treestruct BinTreeNode{T data;                                              //dataBinTreeNode<T>* lChild, *rChild;    //pointer points to left child and right childBinTreeNode() :lChild(NULL), rChild(NULL){};//constructorBinTreeNode(T d, BinTreeNode<T> *l=NULL, BinTreeNode<T>*r=NULL){data = d;lChild = l;rChild=r;}};template<class T>//class definitionclass BinTree{public:BinTree() :root(NULL){}BinTree(T data){value = data;root = NULL;}~BinTree(){destroy(root);}int Size(){return Size(root);}bool isEmpty(){return (root == NULL) ? true : false;}BinTreeNode<T> *Parent(BinTreeNode<T> *current){return (root == NULL || current == root) ? NULL : Parent(root,current);}BinTree<T> *LeftChild(BinTreeNode<T> *current){return (current != NULL) ? current->lChild : NULL;}BinTree<T> *RightChild(BinTreeNode<T> *current){return (current != NULL) ? current->rChild : NULL;}BinTreeNode<T> *getRoot(){return root;}void CreateBinTree(istream& in,BinTreeNode<char> *subtree);private:BinTreeNode<T> *root;T value;void destroy(BinTreeNode<T> *subTree);BinTreeNode<T> *Parent(BinTreeNode<T>*subTree,BinTreeNode<T>*current);public:void Traverse(BinTreeNode<T> *subTree, ostream& out);friend istream& operator>>(istream& in,BinTree<char>& Tree);friend ostream& operator<<(ostream& out, BinTree<char>& Tree);};

//BinTree.cpp#include"BinTree.h"#include<iostream>#include<stack>using namespace std;template<class T>void BinTree<T>::destroy(BinTreeNode<T> *subTree){if (subTree != NULL){destroy(subTree->lChild);//delete left subTree  recucivelydestroy(subTree->rChild);   //delete right subTree recucivelydelete subTree;}}template<class T>BinTreeNode<T> *BinTree<T>::Parent(BinTreeNode<T> *subTree, BinTreeNode<T> *current){if (subTree == NULL)return NULL;if (subTree->lChild == current || subTree->rChild == current)return subTree;return Parent(subTree->lChild, current);return Parent(subTree->rChild, current);}//create binary tree using generalized listvoid CreateBinTree(istream& in, BinTreeNode<char> *&subTree){stack<BinTreeNode<char> *>s;subTree = NULL;BinTreeNode<char> *p, *t;int k;            //tag,1 for left,2 for rightint count = 0;     //index of string,point to the current handlingchar ch;in >> ch;while (ch != '#'){switch (ch){case '(':{s.push(p);k = 1;break;}case ')':{t = s.top();s.pop();break;}case ',':{k = 2;break;}default:{   p = new BinTreeNode<char>(ch);   if (subTree == NULL)   subTree = p;   else if (k == 1)   {   t = s.top();   t->lChild = p;   }   else   {   t = s.top();   t->rChild = p;   }}}in >> ch;}cout << "Create successfully!" << endl;}template<class T>void BinTree<T>::Traverse(BinTreeNode<T>*subTree, ostream&out){if (subTree != NULL){out << subTree->data << "  ";Traverse(subTree->lChild, out);Traverse(subTree->rChild, out);}}//template<class T>istream& operator>>(istream& in, BinTree<char>&Tree){CreateBinTree(in, Tree.root);return in;}//template<class T>ostream& operator<< (ostream&out, BinTree<char>&Tree){out << "Traverse the binary tree:" << endl;Tree.Traverse(Tree.root, out);out << endl;return out;}int main(){BinTree<char> bintree;BinTreeNode<char> *bTreeNode = NULL;cout << "Input generalized list,end with#:" << endl;cin >> bintree;cout << bintree;return 0;}

测试结果：