Submission #883950

#	Time	Username	Problem	Language	Result	Execution time	Memory
883950		OAleksa	Bitaro’s Party (JOI18_bitaro)	C++14	0 / 100	4 ms	12892 KiB

bitaro

#include<bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define int long long
const int N = 1e5 + 69;
const int B = 320;
int n, m, q, deg[N], cnt[N], dp[N], deg1[N], d[N];
vector<int> g[N], in[N];
set<pair<int, int>> bst[N];
vector<int> dis[B];
signed main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
  int tt = 1;
	//cin >> tt;
  while (tt--) {
   	cin >> n >> m >> q;
   	for (int i = 1;i <= m;i++) {
   		int a, b;
   		cin >> a >> b;
   		if (a > b)
   			swap(a, b);
   		g[a].push_back(b);
   		in[b].push_back(a);
   		deg[b]++;
   		deg1[b]++;
   	}
   	queue<int> que;
   	vector<int> p;
   	for (int i = 1;i <= n;i++) {
   		if (deg[i] == 0) {
				que.push(i);
			}
   	}
   	while (!que.empty()) {
   		auto v = que.front();
   		que.pop();
   		for (auto u : g[v]) {
   			--deg[u];
   			dp[u] = max(dp[u], dp[v] + 1);
   			que.push(u);
   		}
   	}
   	vector<int> t(n);
   	iota(t.begin(), t.end(), 1);
   	sort(t.begin(), t.end(), [&](int i, int j) {
   		return dp[i] < dp[j];
   	});
   	for (int i = 0;i < min(2 * B, n);i++) {
   		p.push_back(t[i]);
   	}
   	sort(p.begin(), p.end());
   	for (int j = 0;j < (int)p.size();j++) {
			for (int i = 1;i <= n;i++)	
				dp[i] = 0, deg[i] = deg1[i];
			que.push(p[j]);
			while (!que.empty()) {
   			auto v = que.front();
   			que.pop();	
   			for (auto u : g[v]) {
   				--deg[u];
   				dp[u] = max(dp[u], dp[v] + 1);
   				if (deg[u] == 0)
   					que.push(u);
   			}
   		}
   		for (int i = 1;i <= n;i++)
   			dis[j].push_back(dp[i]);
   	}
   	while (q--) {
   		int s, c;
   		cin >> s >> c;
   		int a[c];
   		for (int i = 0;i < c;i++) 
   			cin >> a[i];
   		int ans = 0;
   		if (c < B) {
   			sort(a, a + c);
   			for (int i = 0;i < (int)p.size();i++) {
   				auto u = lower_bound(a, a + c, p[i]) - a;
   				if (u == c || a[u] != p[i]) 
   					ans = max(ans, dis[i][s - 1]);
   			}
   		}
   		else {
   			for (int i = 1;i <= n;i++)
   				d[i] = cnt[i] = 0;
   			for (int i = 1;i <= n;i++)
   				cnt[a[i]] = 1;
   			que.push(s);
   			while (!que.empty()) {
   				auto v = que.front();
   				que.pop();
   				for (auto u : in[v]) {
   					if (d[u] >= d[v] + 1)
   						continue;
   					d[u] = d[v] + 1;
   					que.push(v);
   				}
   			}
   			for (int i = 1;i <= n;i++) {
   				if (!cnt[i])
   					ans = max(ans, d[i]);
   			}
   		}
   		cout << ans << '\n';
   	}
	}
	return 0;
}

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