#include<bits/stdc++.h>
using namespace std;

int cnt;
string str;

typedef struct Tree{
	char v;
	Tree *l, *r;
}Tree; 

Tree *build() //建树
{
	char c = str[cnt ++];
	
	if(c == '0') return  NULL;
	
	Tree *root = new Tree(); 
	
	root -> v = c;
	root -> l = build();
	root -> r = build();
	
	return root;
} 

void traversal_piror(Tree *root) //前序遍历
{
	if(!root) return;
	
	printf("%c ", root -> v);
	traversal_piror(root -> l);
	traversal_piror(root -> r);
}

void traversal_mid(Tree *root) //中序遍历
{
	if(!root) return;
	
	traversal_mid(root -> l);
	printf("%c ", root -> v);
	traversal_mid(root -> r);
}

void traversal_rear(Tree *root)//后序遍历
{
	if(!root) return;
	
	traversal_rear(root -> l);
	traversal_rear(root -> r);
	printf("%c ", root -> v);
}
 
void get_ans(Tree *root) //层序遍历求叶子结点个数
{
	int ans = 0;
	queue<Tree*> q;
	
	if(root) q.push(root);
	
	while(q.size())
	{
		int n = q.siz...