Submission #62574

#	Time	Username	Problem	Language	Result	Execution time	Memory
62574		qkxwsm	Bitaro’s Party (JOI18_bitaro)	C++11	7 / 100	2069 ms	129256 KiB

bitaro

/*
PROG: joi183b
LANG: C++11
    _____
  .'     '.
 /  0   0  \
|     ^     |
|  \     /  |
 \  '---'  /
  '._____.'
 */
#include <bits/stdc++.h>

using namespace std;

template<class T>
void readi(T &x)
{
	T input = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
	{
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		input = input * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		input = -input;
	}
	x = input;
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int aout[20];
	int ilen = 0;
	while(output)
	{
		aout[ilen] = ((output % 10));
		output /= 10;
		ilen++;
	}
	for (int i = ilen - 1; i >= 0; i--)
	{
		putchar(aout[i] + '0');
	}
	return;
}
template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
long long randomize(long long mod)
{
	return ((1ll << 30) * rand() + (1ll << 15) * rand() + rand()) % mod;
}

#define MP make_pair
#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-20;

#define MAGIC 107
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 200013

template<class T>
T normalize(T x, T mod = INF)
{
	return (((x % mod) + mod) % mod);
}

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, vector<int> > piv;

int N, M, Q;
vector<int> edge[MAXN];
bool seen[MAXN];
vector<piv> queries[MAXN];
vector<pii> best[MAXN];
int dist[MAXN];
int ans[MAXN];

int32_t main()
{
	ios_base::sync_with_stdio(0); 
	srand(time(0));
	//	cout << fixed << setprecision(12);	
	//	cerr << fixed << setprecision(12);
	if (fopen("joi183b.in", "r"))
	{	
		freopen ("joi183b.in", "r", stdin);
		freopen ("joi183b.out", "w", stdout);
	}
	cin >> N >> M >> Q;
	for (int i = 0; i < M; i++)
	{
		int u, v;
		cin >> u >> v;
		u--;
		v--;
		edge[v].PB(u);
	}
	for (int i = 0; i < Q; i++)
	{
		int u, sz;
		cin >> u >> sz;
		u--;
		vector<int> vec;
		for (int j = 0; j < sz; j++)
		{
			int v;
			cin >> v;
			v--;
			vec.PB(v);
		}
		queries[u].PB(MP(i, vec));
		ans[i] = -1;
	}
	for (int i = 0; i < N; i++)
	{
		dist[i] = -INF;
	}
	for (int u = 0; u < N; u++)
	{
		vector<int> active;
		dist[u] = 0;
		active.PB(u);
		for (int v : edge[u])
		{
			for (pii x : best[v])
			{
				ckmax(dist[x.se], x.fi + 1);
				active.PB(x.se);
			}
		}
		sort(active.begin(), active.end());
		active.erase(unique(active.begin(), active.end()), active.end());
		for (int v : active)
		{
			best[u].PB(MP(dist[v], v));
		}
		sort(best[u].begin(), best[u].end());
		reverse(best[u].begin(), best[u].end());
		while(best[u].size() > MAGIC)
		{
			best[u].pop_back();
		}
		for (int v : edge[u])
		{
			for (pii x : best[v])
			{
				dist[x.se] = -INF;
			}
		}
	}
//	for (int i = 0; i < N; i++)
//	{
//		cerr << "vertex " << i << ":\n";
//		for (pii x : best[i])
//		{
//			cerr << "dist " << x.fi << " vertex " << x.se << '\n';
//		}
//	}
	for (int u = 0; u < N; u++)
	{
		for (piv q : queries[u])
		{
			int qid = q.fi;
			vector<int> bans = q.se;
			for (int v : bans)
			{
				seen[v] = true;
			}
			if (bans.size() < MAGIC)
			{
				for (auto y : best[u])
				{
					int v = y.se;
					if (!seen[v])
					{
						ans[qid] = y.fi;
						break;
					}
				}
			}
			else
			{
				for (int v = u; v >= 0; v--)
				{
					dist[v] = -INF;
				}
				dist[u] = 0;
				for (int v = u; v >= 0; v--)
				{
//					cerr << v << ' ' << dist[v] << endl;
					for (int w : edge[v])
					{
						ckmax(dist[w], dist[v] + 1);
					}
					if (!seen[v])
					{
						ckmax(ans[qid], dist[v]);
					}
				}
			}
			for (int v : bans)
			{
				seen[v] = false;
			}
		}
		//if sum of # of u-queries is >= sqrtN you can probably brute
		//otherwise sum of banned is <sqrtN, so you store the best sqrtN guys?
	}
	for (int i = 0; i < Q; i++)
	{
		cout << ans[i] << '\n';
	}
	//longest path starting from u that doesn't end at one of these specific nodes
	//so you just have a graph with no cycles and you can toposort
	//	cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int32_t main()':
bitaro.cpp:133:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen ("joi183b.in", "r", stdin);
   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:134:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen ("joi183b.out", "w", stdout);
   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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