TG T2 magic

因为我太菜了，所以写了个暴力，但是洛谷RE爆零，CCF那却没事，这是什么情况呢？

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
inline void read(int &x)
{
	x=0;int flag(1);char c(0);
	for(;!isdigit(c);c=getchar())if(c=='-')flag=-1;
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	x*=flag;
}
int a[105];
vector<int>G[105];
map<int,map<ll,int> >f;
int n,m,q,u,v,max_day(-1);
int main()
{
//	freopen("magic.in","r",stdin);
//	freopen("magic.out","w",stdout);
	read(n);read(m);read(q);
	for(register int i(1);i<=n;++i)
	{
		read(f[i][0]);
	}
	for(register int i(1);i<=m;++i)
	{
		read(u);read(v);
		G[u].push_back(v);
		G[v].push_back(u);
	}
	for(register int i(1);i<=q;++i)
	{
		read(a[i]);
		max_day=max(max_day,a[i]);
	}
	for(register int i(1);i<=max_day;++i)
	{
		for(register int u(1);u<=n;++u)
		{
			f[u][i]=f[G[u][0]][i-1];
			int siz=G[u].size();
			for(register int j(1);j<siz;++j)
			{
				f[u][i]^=f[G[u][j]][i-1];
			}
		}
	}
	for(register int i(1);i<=q;++i)
	{
		printf("%d\n",f[1][a[i]]);
	}
	return 0;
}