1208. Legendary Teams Contest

http://acm.timus.ru/problem.aspx?space=1&num=1208

水题

代码：

#include<iostream>

#include<cstdio>

#include<cstring>

#include<string>

#include<vector>

#include<queue>

#include<map>

#include<set>

#include<stack>

#include<algorithm>

#include<cmath>



using namespace std;

//#pragma comment(linker,"/STACK:1000000000,1000000000")



#define LL long long



const int INF=0x3f3f3f3f;

const int N=35;

int num[N][5];

bool select[N*N];

map<string,int>str;

int n,ans;

void dfs(int x,int k)

{

    if(x==n)

    {

        ans=max(ans,k);

        return ;

    }

    dfs(x+1,k);

    int j;

    for(j=0;j<3;++j)

    if(select[num[x][j]]==true)

    return;

    for(j=0;j<3;++j)

    select[num[x][j]]=true;

    dfs(x+1,k+1);

    for(j=0;j<3;++j)

    select[num[x][j]]=false;

}

int main()

{

    while(cin>>n)

    {

        str.clear();

        int I=0;

        for(int i=0;i<n;++i)

        for(int j=0;j<3;++j)

        {

            string stmp;

            cin>>stmp;

            if(str.find(stmp)==str.end())

            {str[stmp]=I;num[i][j]=I++;}

            else

            num[i][j]=str[stmp];

        }

        ans=0;

        memset(select,false,sizeof(select));

        dfs(0,0);

        cout<<ans<<endl;

    }

    return 0;

}