#include <bits/stdc++.h>
#define rep(i,j,k) for(int i=(j);i<=(k);i++)
#define per(i,j,k) for(int i=(j);i>=(k);i--)
#define uint unsigned int
#define ll long long
#define ull unsigned long long
#define db double
#define ldb long double
#define pii pair<int,int>
#define pll pair<ll,ll>
#define mkp make_pair
#define eb emplace_back
#define SZ(S) (int)S.size()
//#define mod 998244353
//#define mod 1000000007
#define inf 0x3f3f3f3f
#define linf 0x3f3f3f3f3f3f3f3f
using namespace std;

template <class T>
void chkmax(T &x,T y){
	if(x < y) x = y;
}

template <class T>
void chkmin(T &x,T y){
	if(x > y) x = y;
}

inline int popcnt(int x){
	return __builtin_popcount(x);
}

inline int ctz(int x){
	return __builtin_ctz(x);
}


/*ll power(ll p,int k = mod - 2){
	ll ans = 1;
	while(k){
		if(k % 2 == 1) ans = ans * p % mod;
		p = p * p % mod;
		k /= 2;	
	}
	return ans;
}*/
int n,m,q;
vector <int> G[100005];

int vis[100005];
void dfs(int u){
	vis[u] = 1;
	for(int v:G[u]){
		if(vis[v]) continue;
		dfs(v);
	}
}
int main(){
	scanf("%d%d%d",&n,&m,&q);
	rep(i,1,m){
		int u,v;
		scanf("%d%d",&u,&v);
		G[u].eb(v);
	}
	dfs(1);
	rep(u,1,n) assert(vis[u]);
	return 0;
}

这份代码在 #15 RE 了。

为啥 thuwc 数据题还能挂的，太不牛了我们 thuwc