hdu 2999 Stone Game, Why are you always there? （简单SG，有个优化）

int sg[1005];
int n,m,k;
int a[105];

int dfs(int x){
    if(sg[x]!=-1)
        return sg[x];
    bool vis[1005]={0};
    rep(i,1,n){
        if(x<a[i]) break;
        for(int j=1;j+a[i]-1<=x;++j){
            int t1=0;
            t1=t1^dfs(j-1);
            t1=t1^dfs(x-j-a[i]+1);
            vis[t1]=true;
        }
    }
    for(int i=0;;++i){
        if(!vis[i]){
            return sg[x]=i;
        }
    }
}
int main(){
    while(scanf("%d",&n)!=EOF){
        rep(i,1,n) scanf("%d",&a[i]);
        sort(a+1,a+1+n);

        ///去重，时间一下缩短一半，这数据....
        int t1=0; int b[105]; b[0]=-1;
        rep(i,1,n) if(a[i]!=b[t1]) b[++t1]=a[i];
        n=t1;
        rep(i,1,n) a[i]=b[i];

        scanf("%d",&m);
        mem(sg,-1);
        while(m--){
            scanf("%d",&k);
            if(!dfs(k))
                puts("2");
            else
                puts("1");
        }
    }
}