题目链接：https://pintia.cn/problem-sets/1120858298571182080/problems/1120858729158430720
package pat树;//acimport java.util.Scanner;public class Main86前序序列创建二叉树 {static String s;static node root;static int i;static char a;public static node build() {a = s.charAt(i++);node jiedian = new node();if (a != '#') {jiedian.v = a;jiedian.le = build();jiedian.ri = build();} else {jiedian = null;}return jiedian;}public static void print(node root) {if (root != null) {print(root.le);System.out.print(root.v + " ");print(root.ri);}}public static void main(String[] args) {Scanner in = new Scanner(System.in);while (in.hasNext()) {s = in.nextLine();root = build();print(root);System.out.println();i=0;}}}class node {char v;node le;node ri;}