XDOJ_1084_dfs

http://acm.xidian.edu.cn/problem.php?id=1084

小数据，直接dfs暴力来做，今天各种细节出错- -！

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

int n,u,v,vis[15],sco[15],ans,k;
vector<int> pre[15];

void dfs(int x,int sum)
{
    if(x == 0)
    {
        ans = max(ans,sum);
        return;
    }
    for(int i = 1;i <= 10;i++)
    {
        if(vis[i])    continue;
        int flag = 1;
        for(int j = 0;j < pre[i].size();j++)
        {
            if(!vis[pre[i][j]])
            {
                flag = 0;
                break;
            }
        }
        if(!flag)    continue;
        vis[i] = 1;
        dfs(x-1,sum+sco[i]);
        vis[i] = 0;
    }
}
int main()
{
    while(~scanf("%d",&n))
    {
        memset(vis,0,sizeof(vis));
        for(int i = 1;i <= 10;i++)    pre[i].clear();
        while(n--)
        {
            scanf("%d%d",&u,&v);
            pre[v].push_back(u);
        }
        for(int i = 1;i <= 10;i++)    scanf("%d",&sco[i]);
        scanf("%d",&k);
        ans = 0;
        dfs(k/3,0);
        if(ans >= 60)    printf("%d\n",ans);
        else    printf("I chose to die\n");
    }
    return 0;
}