HDU_1524 A Chess Game (sg函数)

　　/*今天一翻以前做的sg函数的题，这题原来的代码居然跑781MS， 我晕！又重新写
了一遍，开始vis数组定义成全局变量了，WA。。。T_T

My Code(78+MS)：*/

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

const int N = 1005;

struct node{
    int num;
    int edg[N];
}e[N];

int sg[N];


int mex(int t){
    if(sg[t] != -1)    return sg[t];
    int i;
    bool vis[N] = {0};

    for(i = 0; i < e[t].num; i++){
        vis[mex(e[t].edg[i])] = 1;
    }
    for(i = 0; ; i++){
        if(!vis[i]){
            sg[t] = i;
            break;
        }
    }
    return sg[t];
}

int main(){
    //freopen("data.in", "r", stdin);

    int n, i, j, m, flag, k;
    while(~scanf("%d", &n)){
        memset(e, 0, sizeof(e));
        for(i = 0; i < n; i++){
            scanf("%d", &e[i].num);
            for(j = 0; j < e[i].num; j++){
                scanf("%d", &e[i].edg[j]);
            }
        }
        for(i = 0; i < N; i++){
            sg[i] = -1;
        }
        for(i = 0; i < n; i++){
            mex(i);
        }
        while(scanf("%d", &m), m){
            flag = 0;
            while(m--){
                scanf("%d", &k);
                flag ^= sg[k];
            }
            if(flag)    puts("WIN");
            else    puts("LOSE");
        }
    }
    return 0;
}