Submission #985641

#	Time	Username	Problem	Language	Result	Execution time	Memory
985641		SmuggingSpun	Bitaro’s Party (JOI18_bitaro)	C++14	0 / 100	2 ms	3596 KiB

bitaro

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
template<class T>void maximize(T& a, T b){
	if(a < b){
		a = b;
	}
}
int n, m, q;
namespace sub12{
	const int lim = 1e5 + 5;
	vector<int>e[lim];
	int deg[lim], dp[lim];
	void solve(){
		memset(deg, 0, sizeof(deg));
		for(int _ = 0; _ < m; _++){
			int u, v;
			cin >> u >> v;
			e[u].emplace_back(v);
			deg[v]++;
		}
		int t, y;
		cin >> t >> y;
		bitset<lim>busy;
		busy.reset();
		for(int _ = 0; _ < y; _++){
			int x;
			cin >> x;
			busy.set(x);
		}
		queue<int>Q;
		memset(dp, -1, sizeof(dp));
		for(int i = 1; i <= n; i++){
			if(deg[i] == 0){
				Q.push(i);
				dp[i] = -busy.test(i);
			}
		}
		while(!Q.empty()){
			int u = Q.front();
			Q.pop();
			for(int& v : e[u]){
				maximize(dp[v], dp[u] + 1);
				if(--deg[v] == 0){
					Q.push(v);
				} 
			}
		}
		cout << dp[t];
	}
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	cin >> n >> m >> q;
	if(q == 1){
		sub12::solve();
	}
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:55:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |   freopen(taskname".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86