树的镜面映射

java实现

import java.io.*;
import java.util.*;

public class Main {

    static final int MAXNODE = 1024;

    public static class btNode {
        char value;
        btNode left;
        btNode right;
    }

    static Stack<btNode> s = new Stack<btNode>();
    static Queue<btNode> q = new LinkedList<btNode>();
    static int index = 0;
    static int max;

    static btNode buildTree(String nodeList[]) {
        if (index > max - 1) {
            return null;
        }
        char value = nodeList[index].charAt(0);
        int flag = Character.getNumericValue(nodeList[index].charAt(1));
        index++;

        if (value == '$') {
            return null;
        }

        btNode tmpNode = new btNode();
        tmpNode.value = value;

        if (flag == 0) {
            tmpNode.left = buildTree(nodeList);
            tmpNode.right = buildTree(nodeList);
        }

        return tmpNode;
    }

    static void printTree(btNode root) {
        while(root != null) {
            s.push(root);
            root = root.right;
        }

        while (!s.empty()) {
            System.out.print(s.peek().value + " ");
            q.add(s.pop());
        }

        while (!q.isEmpty()) {
            btNode tmp = q.poll();

            if (tmp.left != null) {
                printTree(tmp.left);
            }

        }
    }
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
//        String str = "a0 b0 $1 c0 d0 $1 e1 f1 $1";
//        max = 9;
        max = Integer.parseInt(br.readLine());
        String str = br.readLine();
        String nodeList[] = str.split(" ");
        btNode root = buildTree(nodeList);
        printTree(root);
    }

}