Submission #400395

#	Time	Username	Problem	Language	Result	Execution time	Memory
400395		nikatamliani	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	1398 ms	95172 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;
void maxi(int &x, int y) {
	if(x < y) x = y;
}
const int C = 100;
bool vis[100005];
void merge(vector<pair<int, int>> &a, const vector<pair<int, int>> &b) {
	vector<pair<int, int>> c;
	int n = (int)a.size(), m = (int)b.size();
	for(int i = 0, j = 0; i < n || j < m;) {
		if((int)c.size() == C) break;
		if(i < n && vis[a[i].second]) { ++i; continue; }
		if(j < m && vis[b[j].second]) { ++j; continue; }
		if(j == m || (i < n && a[i].first > b[j].first+1)) {
			c.push_back(a[i]);
			vis[a[i++].second] = 1;
		} else {
			c.push_back({b[j].first+1, b[j].second});
			vis[b[j++].second] = 1;
		}
	}
	for(const auto &p : c) vis[p.second] = 0;
	a = c;
}
int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	int n, m, q;
	cin >> n >> m >> q;
	vector<vector<int>> g(n+1);
	vector<vector<int>> r(n+1);
	for(int i = 1; i <= m; ++i) {
		int u, v; cin >> u >> v;
		g[u].push_back(v);
		r[v].push_back(u);
	}
	vector<int> dst(n+1);
	vector<vector<pair<int, int>>> list(n+1); 
	for(int i = 1; i <= n; ++i) {
		for(int x : r[i]) {
			merge(list[i], list[x]);
		}
		if((int)list[i].size() < C) list[i].push_back({0, i});
	}
	vector<bool> blocked(n+1);
	vector<int> dp(n+1);
	blocked[0] = 1;
	while(q--) {
		int t, x; cin >> t >> x;
		vector<int> v(x);
		for(int i = 0; i < x; ++i) {
			cin >> v[i]; 
			blocked[v[i]] = 1;
		}
		int ans = -1;
		if(x < C) {
			for(pair<int, int> p : list[t]) {
				if(!blocked[p.second]) {
					ans = p.first;
					break;
				}
			}
		} else {
			for(int i = 1; i <= t; ++i) {
				dp[i] = -1e6;
				if(!blocked[i]) {
					dp[i] = 0;
				}
				for(int x : r[i]) {
					maxi(dp[i], dp[x]+1);
				}
			}
			ans = dp[t];
		}
		if(ans < 0) ans = -1;
		cout << ans << '\n';
		for(int i : v) blocked[i] = 0;
	}
}

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