POJ3087 Shuffle'm Up 简单模拟

#include<cstdio>
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cmath>
#include<map>
#include<queue>
#include<stdlib.h>
#include<string>
#include<set>
using namespace std;
typedef long long LL;
const int maxn=1005;
const int INF=0x3f3f3f3f;
set<string>s;
char a[maxn],b[maxn],now[maxn*2];
string res;
int ans,c,T;
void dfs(int pos)
{
int x=1,y=1;
for(int i=1; i<=c*2; ++i)
{
if(i%2)now[i]=b[y++];
else now[i]=a[x++];
}
now[c*2+1]='\0';
string temp=now+1;
if(temp==res)
{
ans=pos;
return;
}
if(s.find(temp)==s.end())
s.insert(temp);
else return;
for(int i=1; i<=c; ++i)
{
a[i]=now[i];
b[i]=now[i+c];
}
dfs(pos+1);
}
int main()
{
scanf("%d",&T);
for(int i=1; i<=T; ++i)
{
s.clear();
scanf("%d%s%s",&c,a+1,b+1);
cin>>res;
ans=INF;
dfs(1);
printf("%d ",i);
if(ans==INF)printf("-1\n");
else printf("%d\n",ans);
}
return 0;
}