二叉树的链式存储

一、实验内容

1、自己确定一个二叉树（树结点类型、数目和结构自定）利用链式存储结构方法存储。实现树的构造，并完成：

1）用前序遍历、中序遍历、后序遍历输出结点数据；

2）以合理的格式，输出各个结点和双亲、孩子结点信息；

3）输出所有的叶子结点信息；

二、源代码

#include<iostream>
#include<string>
const int MAXSIZE = 100;
using namespace std;
struct Node {
	Node*lchild;
	Node*rchild;
	string data;
};
class  Tree {
private:
	Node*root;
	void release(Node*bt);
	Node*Create(Node*bt);
	void preorder(Node*bt);
	void inorder(Node*bt);
	void postorder(Node*bt);
	void print(Node*bt);//输出叶子结点
	void printlist(Node*bt);//输出
public:
	void preorder(){preorder(root);}//前序遍历
	void inorder() { inorder(root); }//中序遍历
	void postorder() { postorder(root); }//后序遍历
	void leverorder();//层序遍历
	Tree() { root = Create(root); }
	~Tree() { release(root); }
	void print() { print(root); }
	void printlist() { printlist(root); }
	
};

Node*Tree::Create(Node*bt) {
	string ch;
	cout << "输入数据ch：";
	cin >> ch;
	if (ch == "NULL") { bt = NULL; }
	else {
		bt = new Node;
		bt->data = ch;
		cout << "输入左孩子：";
		bt->lchild = Create(bt->lchild);
		cout << "输入右孩子：";
		bt->rchild = Create(bt->rchild);
	}
	return bt;
}

void Tree::release(Node*bt) {

	if (bt != NULL) {
		release(bt->lchild);
		release(bt->rchild);
		delete bt;
	}
}

void Tree::preorder(Node*bt) {
	if (bt == NULL) {
		return;
	}
	else {
		cout << bt->data << "\t";
		preorder(bt->lchild);
		preorder(bt->rchild);
	}

}

void Tree::inorder(Node*bt) {
	if (bt == NULL) {
		return;
	}
	else {
		inorder(bt->lchild);
		cout << bt->data << "\t";
		inorder(bt->rchild);
	}
}
void Tree::postorder(Node*bt) {
	if (bt == NULL) {
		return;
	}
	else {
		postorder(bt->lchild);
		postorder(bt->rchild);
		cout << bt->data << "\t";
	}
}
void Tree::leverorder() {
	int front = -1; int rear = -1; Node*Q[MAXSIZE];
	if (root == NULL) { cout << "NULL"; }
	else {
		Q[++rear] = root;
		while (front != rear) {

			Node*q = new Node;
			q = Q[++front];
			cout << q->data << "\t";
			if (q->lchild != NULL) { Q[++rear] = q->lchild; }
			if (q->rchild != NULL) { Q[++rear] = q->rchild; }
		}

	}
}

void Tree::print(Node*bt) {
	if(bt!=NULL){
		if (!bt->lchild && !bt->rchild)
			cout << bt->data << '\t';
		print(bt->lchild);
		print(bt->rchild);
	}
}

void Tree::printlist(Node*bt) {
	if (bt == NULL)return;
	else{
		if (bt != NULL&&bt->data != "NULL")
			cout << "结点数据为：" << bt->data << endl;
		if (bt->lchild != NULL)
			cout << "左孩纸：" << bt->lchild->data << endl;
		if (bt->rchild != NULL)
			cout << "右孩纸：" << bt->rchild->data << endl;
		cout << "\n";
	}	
	printlist(bt->lchild);
	printlist(bt->rchild);

}

int main() {
	Tree T;
	cout << "\n";
	cout << "前序遍历：";
	T.preorder();
	cout << "\n";
	cout << "中序遍历：";
	T.inorder();
	cout << "\n";
	cout << "后序遍历：";
	T.postorder();
	cout << "\n";
	cout << "层序遍历：";
	T.leverorder();
	cout << "\n";
	cout << "输出所有结点的关系：" << endl;
	T.printlist();
	cout << "\n";
	cout << "输出所有叶子结点：";
	T.print();
	cout << "\n";
	cout << "下期美食介绍敬请期待~~";
}

三、实验结果

四、总结与反思

1、二叉链表实验出于安全性考虑，把函数的实际算法放在private中，当对象要调用函数时要通过public函数调用。

2、层序遍历是使用队列进行操作。这是比较难懂的一个点