这道题感觉挺有意思的，考查了二叉树的层序遍历和中序遍历。
需要注意的地方：
1.标记空结点
2.交换左右子树后层序遍历和中序遍历
3.找树根

#include<cstdio>
#include<vector>
#include<iostream>
#include<cstring>
#include<queue>
using namespace std;

vector<int> child[15],level,in;
void levelorder(int root){
	queue<int> q;
	q.push(root);
	while(!q.empty()){
		int tmp = q.front();
		q.pop();
		level.push_back(tmp);
		for(int i=1;i>=0;i--){
			if(child[tmp][i] != -1)  q.push(child[tmp][i]);
		}
	}
}
void inorder(int root){
	if(root == -1) return;
	inorder(child[root][1]);
	in.push_back(root);
	inorder(child[root][0]);
}
int start[15];
int main(){
	int n;
	char left,right;
	memset(start,-1,sizeof(start));
	scanf("%d",&n);
	for(int i=0;i<n;i++){
		getchar();
		scanf("%c %c",&left,&right);
		if(left >='0' && left <= 10 +'0'){
			child[i].push_back(left-'0');
			start[left-'0']=i;
		}else{
			child[i].push_back(-1);
			start[left-'0']=i;
		}
		if(right >='0' && right <= 10 + '0'){
			child[i].push_back(right - '0');
			start[right-'0']=i;
		}else{
			child[i].push_back(-1);
			start[right-'0']=i;
		}
	}
	int root=0;
	for(int i=0;i<n;i++){
		if(start[i]==-1){
			root = i;
			break;
		}
	}
	//printf("%d\n",root);

	levelorder(root);
	inorder(root);
	for(int i=0;i<level.size();i++){
		if(i>0) printf(" ");
		printf("%d",level[i]);
	}
	putchar(10);
	for(int i=0;i<in.size();i++){
		if(i>0) printf(" ");
		printf("%d",in[i]);
	}
	
	return 0;
}