Submission #90472

#	Time	Username	Problem	Language	Result	Execution time	Memory
90472		radoslav11	Bitaro’s Party (JOI18_bitaro)	C++14	14 / 100	2048 ms	317492 KiB

bitaro

#include <bits/stdc++.h>
#define endl '\n'
 
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
using namespace std;
template<class T, class T2> inline void chkmax(T &x, const T2 &y) { if(x < y) x = y; }
template<class T, class T2> inline void chkmin(T &x, const T2 &y) { if(x > y) x = y; }
const int MAXN = (int)1e5 + 17 + 42;
const int B = 100;
 
int n, m, q;
vector<int> adj[MAXN];
 
void read()
{
	cin >> n >> m >> q;
	for(int i = 0; i < m; i++)
	{
		int u, v;
		cin >> u >> v;
		adj[v].push_back(u);
	}
}
 
bool ok[MAXN];
 
int _dp[MAXN];
int Tm_vis[MAXN], cnt_t;
int TMS = 0;
 
vector<pair<int, int> > dp[MAXN];
 
int rec(int u)
{
	if(Tm_vis[u] >= cnt_t) return _dp[u];
	Tm_vis[u] = cnt_t;
	if(ok[u]) _dp[u] = 0;
	else _dp[u] = -1e9;
 
	for(int v: adj[u])
		chkmax(_dp[u], rec(v) + 1);
 
	return _dp[u];
}
 
int solve_brute(int u, vector<int> blocked)
{
	for(int x: blocked) ok[x] = 0;
	cnt_t++;
	int ans = rec(u);
	for(int x: blocked) ok[x] = 1;
	return ans < 0 ? -1 : ans;
}
 
bool same[MAXN];
 
bool cmp(pair<int, int> a, pair<int, int> b) { return a.second > b.second; }
 
void solve()
{
	for(int i = 1; i <= n; i++) ok[i] = 1;
 
	for(int u = 1; u <= n; u++)
	{
		dp[u].push_back({u, 0});
		for(auto v: adj[u])
			for(auto it: dp[v])
				dp[u].push_back({it.first, it.second + 1});
 
		sort(dp[u].begin(), dp[u].end());
		vector<pair<int, int> > rl;
	
		for(auto it: dp[u])
			if(rl.empty() || rl.back().first != it.first) rl.push_back(it);
			else rl[rl.size() - 1].second = it.second;
	
		if(rl.size() > B)
        {
         	sort(rl.begin(), rl.end(), cmp);
			while((int)rl.size() > B) rl.pop_back();	
        }
        
      dp[u] = rl;
	}
	while(q--)
	{
		int st, sz;
		vector<int> li;
	
		cin >> st >> sz;
		bool has_large = 0;
		for(int i = 0; i < sz; i++)
		{
			int x;
			cin >> x;
			li.push_back(x);
        }
 
		vector<int> initial_li = li;
 
		if(li.size() >= B)
		{
			cout << solve_brute(st, li) << endl;
			continue;
		}
 
		for(auto it: li) same[it] = 1;
 
		int answer = 0;
		for(auto it: dp[st])
			if(!same[it.first])
				chkmax(answer, it.second);
 
		for(auto it: li) same[it] = 0;
 
		if(answer < 0) answer = -1;
		if(answer == 0)
		{
			for(auto it: initial_li)
				if(it == st) answer = -1;
		}
		
		cout << answer << endl;
	}
}
 
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
 
	read();
	solve();
	return 0;
}
 

Compilation message (stderr)

bitaro.cpp: In function 'void solve()':
bitaro.cpp:93:8: warning: unused variable 'has_large' [-Wunused-variable]
   bool has_large = 0;
        ^~~~~~~~~

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