20192320杨坤数据结构实验八

《数据结构与面向对象程序设计》实验八报告

课程：《程序设计与数据结构》

班级： 1923

姓名： 杨坤

学号：20192320

实验教师：王自强

实验日期：2020年12月3日

必修/选修： 必修

1.实验内容

参考教材PP16.1,完成链树LinkedBinaryTree的实现（getRight,contains,toString,preorder,postorder）

用JUnit或自己编写驱动类对自己实现的LinkedBinaryTree进行测试，提交测试代码运行截图，要全屏，包含自己的学号信息

课下把代码推送到代码托管平台

基于LinkedBinaryTree，实现基于（中序，先序）序列构造唯一一棵二㕚树的功能，比如给出中序HDIBEMJNAFCKGL和后序ABDHIEJMNCFGKL,构造出附图中的树

用JUnit或自己编写驱动类对自己实现的功能进行测试，提交测试代码运行截图，要全屏，包含自己的学号信息

课下把代码推送到代码托管平台

自己设计并实现一颗决策树

提交测试代码运行截图，要全屏，包含自己的学号信息

课下把代码推送到代码托管平台

输入中缀表达式，使用树将中缀表达式转换为后缀表达式，并输出后缀表达式和计算结果（如果没有用树，正常评分。如果用到了树，即使有小的问题，也酌情给满分）
提交测试代码运行截图，要全屏，包含自己的学号信息

代码

public interface BinaryTreeADT<T> {
    public T getRootElement();
    public boolean isEmpty();
    public int size();
    public int height();
    public boolean contains(T target);
    public BinaryTreeNode find(T target);
    public String IteratorInorder();
    public String IteratorPreorder();
    public String IteratorPostorder();
    public String IteratorLevel();

}

public class BinaryTreeNode<T> {
    protected T element;
    protected BinaryTreeNode left, right;

    public BinaryTreeNode() {
        element = null;
        left = null;
        right = null;
    }

    public BinaryTreeNode(T element) {
        this.element = element;
        left = right = null;
    }

    public BinaryTreeNode getLeft() {
        return left;
    }

    public BinaryTreeNode getRight() {
        return right;
    }

    public void setLeft(BinaryTreeNode left) {
        this.left = left;
    }

    public void setRight(BinaryTreeNode right) {
        this.right = right;
    }

    public BinaryTreeNode find(T target) {
        BinaryTreeNode result = null;
        if (element.equals(target)) return this;
        else {
            if (left != null) result = left.find(target);
            if (right != null) result = right.find(target);
        }
        return result;
    }

    public int count() {
        int counter = 1;
        if (left != null) counter += left.count();
        if (right != null) counter += right.count();
        return counter;
    }

    public int level() {
        int level = 1, max = 0;
        if (left != null) {
            max = left.level();
        }
        if (right != null && right.level() > max) max = right.level();
        return level + max;
    }

    public String IteratorInOrder() {
        String s = "";
        if (left != null) s += left.IteratorInOrder();
        s += this.element.toString() + " ";
        if (right != null) s += right.IteratorInOrder();
        return s;
    }

    public String IteratorPreOrder() {
        String s = "";
        s += this.element.toString() + " ";
        if (left != null) s += left.IteratorPreOrder();
        if (right != null) s += right.IteratorPreOrder();
        return s;
    }

    public String IteratorPostOrder() {
        String s = "";
        if (left != null) s += left.IteratorPostOrder();
        if (right != null) s += right.IteratorPostOrder();
        s += this.element.toString() + " ";
        return s;
    }

    public BinaryTreeNode Insert(char s) {
        BinaryTreeNode result = null;
        if (left == null) {
            left = new BinaryTreeNode(s);
            result=left;
        }
        else if(!left.element.equals('#'))result=left.Insert(s);
        if(result==null){
            if (right == null) {
                right= new BinaryTreeNode(s);
                result=right;
            }
            else if(!right.element.equals('#'))result=right.Insert(s);
        }
        return result;
    }
    public void Insert1(String a,String b) {
        int i = 0, j;
        for (j = 0; b.charAt(j) != a.charAt(i) && j < b.length(); j++) ;
        if (left == null) {
            if(j!=0) {
                left = new BinaryTreeNode(a.charAt(1));
                left.Insert1(a.substring(i + 1, j + 1), b.substring(0, j)); }
        }
        if (right == null) {
            if(j!=b.length()-1) {
                right = new BinaryTreeNode(a.charAt(j + 1));
                right.Insert1(a.substring(j + 1), b.substring(j + 1)); }
        }
    }

}

public class LinkedBinaryTree <T>implements BinaryTreeADT{
    BinaryTreeNode root;
    public LinkedBinaryTree(){
        root=null;
    }
    public LinkedBinaryTree(T element){
        root=new BinaryTreeNode(element);
    }
    public LinkedBinaryTree(T element,LinkedBinaryTree left,LinkedBinaryTree right){
        root=new BinaryTreeNode(element);
        root.setLeft(left.root);
        root.setRight(right.root);
    }
    @Override
    public T getRootElement() {
        if(root==null)return null;
        return (T) root.element;
    }

    @Override
    public boolean isEmpty() {
        if(root==null)return true;
        else return false;
    }
    public LinkedBinaryTree getLeft(){
        if(root==null)return null;
        LinkedBinaryTree result = new LinkedBinaryTree();
        result.root = root.getLeft();
        return result;
    }
    public LinkedBinaryTree getRight(){
        if(root==null)return null;
        LinkedBinaryTree result = new LinkedBinaryTree();
        result.root = root.getRight();
        return result;
    }
    public void CreateTree(String s){
        root=new BinaryTreeNode(s.charAt(0));
        for(int i=1;i<s.length();i++){
            root.Insert(s.charAt(i));
        }
    }
    public void CreateTree1(String a,String b){
        root=new BinaryTreeNode(a.charAt(0));
        root.Insert1(a,b);
    }
    @Override
    public int size() {
        if(root==null)return 0;
        return root.count();
    }

    @Override
    public int height() {
        if(root==null)return 0;
        return root.level();
    }

    @Override
    public boolean contains(Object target) {
        if(root==null)return false;
        T a=(T)target;
        if(root.find(a)==null)return false;
        else return true;
    }

    @Override
    public BinaryTreeNode find(Object target) {
        if(root==null)return null;
        T a=(T)target;
        return root.find(a);
    }

    @Override
    public String IteratorInorder() {
        if(root==null)return null;
        else return root.IteratorInOrder();
    }

    @Override
    public String IteratorPreorder() {
        if(root==null)return null;
        else return root.IteratorPreOrder();
    }

    @Override
    public String IteratorPostorder() {
        if(root==null)return null;
        else return root.IteratorPostOrder();
    }

    @Override
    public String IteratorLevel() {
        String s="";
        int i,j,count=1;
        int t[]=new int[20];
        BinaryTreeNode m[]=new BinaryTreeNode [20];
        m[0]=root;
        t[0]=count;
        for(i=0,j=1,count=2;i!=j;i++){
            if(m[i].left!=null){m[j]=m[i].left;t[j]=t[i]+1;j++;}
            if(m[i].right!=null){m[j]=m[i].right;t[j]=t[i]+1;j++;}
            s+=m[i].element+" ";
            if(t[i+1]!=t[i]) s+="
";
        }
        return s;
    }

    public String ToString(){
        return root.IteratorPreOrder();
    }

}

public class BStest {
    public static void main(String[] args) {
        LinkedBinaryTree tree=new LinkedBinaryTree();
        tree.CreateTree1("ABDHIEJMNCFGKL","HDIBEMJNAFCKGL");
        System.out.println(tree.IteratorLevel());
    }

}

public class decisionTree<T> {


    public static void main(String[] args) {
        String e0 = "开始游戏！选择亚索还是劲夫？";
        String e1 = "你这把选择亚索";
        String E1 = "你这把选择劲夫";
        String m1 = "这把亚索你选择什么天赋呢？";


        String e2 = "这把你亚索选择天赋:迅捷步伐";
        String E2 = "这把你亚索选择天赋:征服者";

        String e3 = "这把你劲夫选择天赋:丛刃";
        String E3 = "这把你劲夫选择天赋:征服者";

        String e4 = "你这把选择走上路";
        String E4 = "你这把选择走中路";

        String e5 = "这把游戏输了，亚索是孤儿";
        String e6 = "这把游戏输了，但是你快乐到了太空";
        String e7 = "这把游戏输了，没有女性角色，劲夫不好发挥";
        String e8 = "这把游戏赢了，万豪带丛刃，劲夫变叶问";
        String E7 = "输了，劲夫倒了（哭腔）";
        String E8 = "劲夫劲夫，全场芜湖";


        String choose = "0";


        BTNode<String> n1, n2, n3, n4, n5, n6, n7, n8, n9, n10, n11, n12, n13, n14, n15, N2;
        TreeNode treeNode = new TreeNode();
        treeNode.insert(e0);
        /*System.out.println(e1);
        treeNode.insert('Y');
        treeNode.insert('N');
        System.out.println(e2);
        treeNode.insert('Y');
        treeNode.insert('N');*/
        //选择英雄
        n1 = treeNode.otherInsert(treeNode.root, e1, E1);
        //选择天赋
        n2 = treeNode.otherInsert(n1.left, e2, E2);
        n3 = treeNode.otherInsert(n1.right, e3, E3);
        //选择对线路
        n4 = treeNode.otherInsert(n2.left, e4, E4);
        n5 = treeNode.otherInsert(n2.right, e4, E4);
        n6 = treeNode.otherInsert(n3.left, e4, E4);
        n7 = treeNode.otherInsert(n3.right, e4, E4);




        //游戏结果
        n8 = treeNode.otherInsert(n4.left, e5, e5);
        n9 = treeNode.otherInsert(n4.right, e6, e6);
        n10 = treeNode.otherInsert(n5.left, e5, e5);
        n11 = treeNode.otherInsert(n5.right, e5, e5);
        n12 = treeNode.otherInsert(n6.left, e7, e7);
        n13 = treeNode.otherInsert(n6.right, e8, e8);
        n14 = treeNode.otherInsert(n7.left, E8, E8);
        n15 = treeNode.otherInsert(n7.right, E7, E7);

        BTNode current = new BTNode();

        Scanner scanner = new Scanner(System.in);
        current = treeNode.root;
       
       
        System.out.println("选择英雄"+"
"+"选择天赋："+"
"+"亚索：迅捷步伐与征服者 "+" 劲夫：丛刃与征服者"+"
"+"选择上路还是中路");

        while (treeNode.size(current) >2 ) {
            System.out.println(current.data);

            System.out.println("选择第一个输入Y第二个输入N");
            if (scanner.nextLine().equalsIgnoreCase("N"))
                current = current.right;
            else current = current.left;


        }
        current=current.left;
        
        System.out.println(current.data);


    }


}

中缀的代码：

public class MiddleToRear {

    public static void main(String[] args) {
        //不用索引扫描表达式,将表达式加入到list中
        String expression;
        Scanner scanner=new Scanner(System.in);
        expression=scanner.next();
        //得到中缀表达式转为list的集合
        List<String> list=getList(expression);
        //将中缀表达式的集合转到后缀表达式的集合
        List<String> rearList=getRearList(list);
        System.out.println("rearList = " + rearList);

        //输出计算结果
        System.out.println(getResult(rearList));


    }

    //中缀表达式的集合转为后缀表达式的集合
    private static List<String> getRearList(List<String> list) {
        ArrayList<String> rearList = new ArrayList<>();
        //定义符号栈
        Stack<String> operatorStack = new Stack<>();
        //定义集合代替数字栈,数字栈本身并没有pop操作,并且最后要倒叙输出,随意用list代替
        ArrayList<String> numList = new ArrayList<>();
        for (String s : list) {
            //如果是个数字
            if (s.matches("\d+")){
                numList.add(s);
            }else if (s.equals("(")){
                operatorStack.push(s);
            }else if (s.equals(")")){
                //符号栈栈顶直到左括号之前的符号放入数字栈
                while (!"(".equals(operatorStack.peek())){
                    numList.add(operatorStack.pop());
                }
                //把左括号弹出来
                operatorStack.pop();
                //判断优先级,当前符号优先级小于等于符号栈栈顶优先级,将符号栈栈顶弹出加入数字栈,
                //直到找到当前符号优先级大于符号栈栈顶优先级为止,再将当前符号加入符号栈
            }else{
                while (operatorStack.size()!=0 && (OperPriority.getPriority(s) <= OperPriority.getPriority(operatorStack.peek()))){
                    numList.add(operatorStack.pop());
                }
                //将当前符号加入符号栈
                operatorStack.push(s);
            }
        }
        //将符号栈中剩余符号加入数字栈
        while (operatorStack.size()!=0){
            numList.add(operatorStack.pop());
        }
        return numList;
    }

    //将中缀表达式的各个字符存到list集合,方面遍历
    private static List<String> getList(String expression) {
        ArrayList<String> list = new ArrayList<>();
        int index=0;
        String str=""; //多位数的拼接
        char c;  //用于存放每次扫描到的结果
        do {
            //判断是否为数字,非数字直接加入list
            c=expression.charAt(index);
            if (c < 48 || c >57){
                list.add(""+c);
            }else {//数字.考虑可能不是一位数,字符串拼接
                str+=c;
                if (index == expression.length()-1){
                    list.add(str);
                }else {
                    if (expression.charAt(index+1) < 48 || expression.charAt(index+1) > 57){
                        list.add(str);
                        str="";
                    }
                }
            }
            index++;
        }while (index < expression.length());
        return list;
    }
    //输出计算结果
    private static int getResult(List<String> list) {
        Stack<String> stack = new Stack<>();
        for (String s : list) {
            //匹配数字
            if (s.matches("\d+")){
                stack.push(s);
            }else {
                int num01=Integer.parseInt(stack.pop());
                int num02=Integer.parseInt(stack.pop());
                int result=0;
                if (s.equals("+")){
                    result=num01+num02;
                }else if (s.equals("-")){
                    result=num02-num01;
                }else if (s.equals("*")){
                    result=num02*num01;
                }else if (s.equals("/")){
                    result=num02/num01;
                }else {
                    throw new RuntimeException("无法解析的字符串");
                }
                stack.push(""+result);
            }
        }
        return Integer.parseInt(stack.pop());
    }


}

截图：

2.实验心得体会

自身的自学能力还要提升，大多数的实验代码都在同学的帮助下完成，在运到困难时，容易感到沮丧，还要多锻炼自己。平时也要多加练习。
这是一个新的软件，一切都是陌生的，在遇到这种问题的时候，多上网搜集资料是非常必要的，同时多家运用学习的app在上面观看相关的视频能够更好的掌握。