Submission #369643

#	Time	Username	Problem	Language	Result	Execution time	Memory
369643		8e7	Bitaro’s Party (JOI18_bitaro)	C++14	7 / 100	2078 ms	13424 KiB

bitaro

//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#define ll long long
#define maxn 100005
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
const int siz = 320;
vector<int> adj[maxn], from[maxn];
vector<pii> pnt[maxn], tmp;

inline bool cmp (pii a, pii b) {
	return a.ss > b.ss;
}


int dp[maxn];
bool part[maxn], found[maxn];
void getdp(int n) {
	for (int i = 1;i <= n;i++) dp[i] = 0;
	for (int i = 1;i <= n;i++) {
		for (int v:adj[i]) {
			dp[v] = max(dp[v], (dp[i] == 0 ? (part[i] ? -1 : 0) : dp[i]) + 1);
		}
	}
}
int main() {
	ios_base::sync_with_stdio(0);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);
		from[b].push_back(a);
	}
	for (int i = 1;i <= n;i++) {
		for (int v:from[i]) {
			for (auto it:pnt[v]) tmp.push_back(make_pair(it.ff, it.ss + 1));
		}
		tmp.push_back(make_pair(i, 0));
		sort(tmp.begin(), tmp.end(), cmp);
		for (int j = 0;j < tmp.size();j++) {
			if (!found[tmp[j].ff]) {
				found[tmp[j].ff] = 1;
				pnt[i].push_back(tmp[j]);
				if (pnt[i].size() >= siz) break;
			}
		}
		//cout << i << endl;
		for (auto v:pnt[i]) found[v.ff] = 0;
		tmp.clear();
	}
	getdp(n);
	while (q--) {
		int ind, yi;
		cin >> ind >> yi;
		vector<int> val;
		for (int i = 0;i < yi;i++) {
			int x;
			cin >> x;
			part[x] = 1;
			val.push_back(x);
		}
		if (yi >= siz) {
			getdp(n);
			if (part[ind] && dp[ind] == 0) cout << -1 << "\n";
			else cout << dp[ind] << "\n";
		} else {
			int ans = -1;
			for (auto v:pnt[ind]) {
				if (!part[v.ff]) ans = max(ans, v.ss);
			}
			cout << ans << "\n";
		}
		for (int i:val) part[i] = 0;
	}
}
/*
5 6 3
1 2
2 4
3 4
1 3
3 5
4 5
4 1 1
5 2 2 3
2 3 1 4 5
 */

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:47:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |   for (int j = 0;j < tmp.size();j++) {
      |                  ~~^~~~~~~~~~~~

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