Submission #1261969

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261969		tminh	Bitaro’s Party (JOI18_bitaro)	C++20	0 / 100	12 ms	8520 KiB

bitaro

#include "bits/stdc++.h"
using namespace std;

#define task ""
#define ll long long
#define endl '\n'
#define fi first
#define se second
#define vall(a) (a).begin(), (a).end()
#define sze(a) (int)a.size()
#define pii pair<int, int>
#define pll pair<ll, ll>


#define ep emplace_back
#define pb push_back
#define pf push_front


const ll mod = 1e9 + 7;
const int N = 1e5 + 5;
const ll oo = 1e18;
const int base = 320;

bool START;

int n, m, d[N], q, a[N];
vector<int> adj[N];
vector<pii> ds[N];

bool vis[N], del[N];

int get(int u) {
	for (int i = 1; i <= n; ++i) {
		vis[i] = false;
		d[i] = 0;
		if (del[i]) d[i] = -1;
	}
	for (int v = 1; v <= u; ++v) {
		for (int p : adj[v]) if (d[p] != -1) {
			d[v] = max(d[v], d[p] + 1); 
			vis[v] = true;
		}
	}
	if (vis[u]) return d[u];
	return -1;
}

inline void solve() {
	for (int u = 1; u <= n; ++u) {
		
		vector<int> tmp;
		for (int p : adj[u]) {
			
			for (auto [len, p_] : ds[p]) {
				if (!vis[p_]) {
					d[p_] = len + 1;
					tmp.pb(p_);
					vis[p_] = true;
				} else d[p_] = max(d[p_], len + 1);
			}
			
		}
		for (int p : tmp) {
			vis[p] = false;
			ds[u].pb(make_pair(d[p], p));
		}
		ds[u].pb(make_pair(0, u));
		sort(vall(ds[u]), greater<pii>());
		while(sze(ds[u]) > base + 1) ds[u].pop_back(); 
	}
	while(q--) {
		int u, x;
		cin >> u >> x;
		for (int i = 1; i <= x; ++i) {
			cin >> a[i];
			del[a[i]] = true;
		}
		
		int ans = -1;
		if (x > base) {
			ans = get(u);
		} else {
			for (auto[len, p] : ds[u]) if (!del[p]) ans = max(ans, len);
		}
		cout << ans << endl;
		for (int i = 1; i <= x; ++i) del[a[i]] = false;
	}
	
	
}


inline void input() {
    cin >> n >> m >> q;
    for(int i = 1; i <= m; ++i) {
    	int u, v;
    	cin >> u >> v;
    	adj[v].pb(u);
    }
    return solve();
}
bool END;

int main() {
    if(fopen(task ".inp", "r")) {
        freopen(task ".inp", "r", stdin);
        freopen(task ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    input();
    
    
    cerr << endl << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << 's' << endl;
    cerr << "Memory: " << fabs ((&END - &START)) / 1048576.0 << "MB\n";
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:107:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |         freopen(task ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:108:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |         freopen(task ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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