题解 | #二叉树遍历#

import java.util.Scanner;

class TreeNode {
    public char val;
    TreeNode left;
    TreeNode right;
    TreeNode() {

    }

    TreeNode(char val) {
        this.val = val;
    }
}

//二叉树的构建及遍历

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String str = in.nextLine();
            TreeNode root = creatTree(str);
            inorder(root);
        }
    }

    public static int i = 0;

    public static TreeNode creatTree(String str) {
        TreeNode root = null;
        if (str.charAt(i) != '#') {
            root = new TreeNode(str.charAt(i));
            i++;
            root.left = creatTree(str);
            root.right = creatTree(str);
        } else {
            i++;
        }
        return root;
    }

    public static void inorder(TreeNode root) {
        if (root == null) {
            return;
        }
        inorder(root.left);
        System.out.print(root.val + " ");
        inorder(root.right);
    }


}