Submission #383484

#	Time	Username	Problem	Language	Result	Execution time	Memory
383484		morato	Bitaro’s Party (JOI18_bitaro)	C++17	14 / 100	2099 ms	224104 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1e5 + 5;
const int MAXS = 200;

vector<int> adj[MAXN], rev[MAXN];

vector<pair<int, int>> caras[MAXN];

int in[MAXN], bosta[MAXN], best[MAXN], dp[MAXN], valid[MAXN];

bool mark[MAXN], blocked[MAXN];

void merge(int a, int b) {
	vector<pair<int, int>> result;
	int j = 0;
	for (int i = 0; i < (int) caras[a].size(); i++) {
		for (; j < (int) caras[b].size() && caras[b][j].first + 1 > caras[a][i].first; j++) {
			result.push_back({caras[b][j].first + 1, caras[b][j].second});
		}
		result.push_back(caras[a][i]);
	}
	for (; j < (int) caras[b].size(); j++) {
		result.push_back({caras[b][j].first + 1, caras[b][j].second});
	}
	caras[a].clear();
	for (auto x : result) {
		if (!mark[x.second] && (int) caras[a].size() < MAXS + 1) {
			caras[a].push_back(x);
			mark[x.second] = true;
		}
	}
	for (auto x : caras[a]) {
		mark[x.second] = false;
	}
}

int solve(int v) {
	if (dp[v] != -1) return dp[v];
	valid[v] = (int) !blocked[v];
	int ans = 0;
	for (int u : rev[v]) {
		ans = max(ans, solve(u) + valid[u]);
		if (valid[u]) valid[v] = 1;
	}
	return dp[v] = ans;
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m, q;
	cin >> n >> m >> q;
	for (int i = 0; i < m; i++) {
		int a, b;
		cin >> a >> b;
		adj[a].push_back(b);
		rev[b].push_back(a);
		in[b]++;
	}
	vector<int> lista;
	for (int i = 1; i <= n; i++) {
		caras[i].push_back({0, i});
		if (!in[i]) lista.push_back(i);
	}
	for (int i = 0; i < (int) lista.size(); i++) {
		int cur = lista[i];
		for (int nxt : adj[cur]) {
			in[nxt]--;
			if (!in[nxt]) lista.push_back(nxt);
			merge(nxt, cur);
		}
	}
	for (int i = 0; i < q; i++) {
		int t, y;
		cin >> t >> y;
		for (int j = 0; j < y; j++) {
			cin >> bosta[j];
			blocked[bosta[j]] = true;
		}
		if (y > MAXS) {
			memset(dp, -1, sizeof dp);
			memset(valid, 0, sizeof valid);
			int ans = (solve(t) == 0 ? blocked[t] ? -1 : 0 : dp[t]);
			cout << ans << '\n';
		} else {
			int ans = -1;
			for (auto x : caras[t]) {
				if (!blocked[x.second]) {
					ans = x.first;
					break;
				}
			}
			cout << ans << '\n';
		}
		for (int j = 0; j < y; j++) {
			blocked[bosta[j]] = false;
		}
	}
	return 0; 
}

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