开O2全WA,关O2全RE，下载测试点1发现输出一样但就是过不了，code:

#include<bits/stdc++.h>
using namespace std;
int num=0;
char mid[11],back[11];
void search(int lmid,int rmid,int lback,int rback)
{
	if (lmid > rmid || lback > rback)
		return ;
	if (back[rback]=='\0')
		return ;
	else
		cout<<back[rback];
	char root=back[rback];
	int rtid;
	for (int i = lmid;i <= rmid;i++)
	{
		if (mid[i]==root)
		{
			rtid=i;
			break;
		}
	}
	int len=rtid-1-lmid;
	search(lmid,rtid-1,lback,lback+len);
	search(rtid+1,rmid,lback+len+1,rback-1);
	return ;
}
int main (){
	while (mid[num]=getchar())
	{
		if (mid[num]=='\n')
			break;
		num++;
	}
	for (int i = 0;i < num;i++)
		cin>>back[i];
	search(0,num-1,0,num-1);
	return 0;
}