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;
}