Submission #94452

#	Time	Username	Problem	Language	Result	Execution time	Memory
94452		aminra	Bitaro’s Party (JOI18_bitaro)	C++14	0 / 100	21 ms	10744 KiB

bitaro

//Smaug never desolated!!
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const int MAXN = (int)100007;
const int block = 1000;
const int infint = (int)1e8 + 3;
const int MOD = (int)1e9 + 7;
const ll inf = (ll)1e18;
int n, m, q, bad[MAXN], dp[MAXN], input[MAXN], prv[MAXN];
pair<int, int> DP[MAXN][block], tmp[block];
vector<int> in[MAXN];
bool cmp(pair<int, int> a, pair<int, int> b)
{
	return a.second > b.second;
}
inline void merge(int a, int b)
{
	int sz = 0;
	vector<int> used;
	for (int i = 0; i < block; i++)
		tmp[i] = {-1, -1};
	int ptr1 = 0, ptr2 = 0;
	while(sz < block)
	{
		while(ptr1 < block && DP[a][ptr1].first != -1 && prv[DP[a][ptr1].first])
			ptr1++;
		while(ptr2 < block && DP[b][ptr2].first != -1 && prv[DP[b][ptr2].first])
			ptr2++;
		pair<int, int> B = {-1, -1};
		if(ptr2 != block && DP[b][ptr2].first != -1)
			B = DP[b][ptr2], B.second++;
		if(cmp(DP[a][ptr1], B))
		{
			tmp[sz] = DP[a][ptr1], ptr1++, sz++;
			int idx = DP[a][ptr1].first;
			if(idx != -1)
				prv[idx] = 1, used.push_back(idx);
		}
		else
		{
			tmp[sz] = B, ptr2++, sz++;
			int idx = B.first;
			if(idx != -1)
				prv[idx] = 1, used.push_back(idx);
		}
	}
	for (int i = 0; i < block; i++)
		DP[a][i] = tmp[i];
	for (auto u : used)
		prv[u] = 0;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	cin >> n >> m >> q;
	for (int i = 0; i < m; i++)
	{
		int u, v;
		cin >> u >> v;
		in[v].push_back(u);
	}
	for (int i = 1; i <= n; i++)
		for (int j = 0; j < block; j++)
			DP[i][j] = {-1, -1};
	DP[1][0] = {1, 0};
	for (int i = 2; i <= n; i++)
	{
		DP[i][0] = {i, 0};
		for (auto u : in[i])
			merge(i, u);
	}
	for (int i = 0; i < q; i++)
	{
		int v, t;
		cin >> v >> t;
		for (int i = 0; i < t; i++)
		{
			cin >> input[i];
			bad[input[i]] = 1;
		}
		if(t >= block)
		{
			memset(dp, -1, sizeof dp);
			dp[v] = 0;
			for (int i = v; i >= 1; i--)
				if(dp[i] != -1)
					for (auto u : in[i])
						dp[u] = max(dp[u], dp[i] + 1);
			int ans = -1;
			for (int i = v; i >= 1; i--)
				if(!bad[i])
					ans = max(ans, dp[i]);
			cout << ans << "\n";
		}
		else
		{
			int ans = -1;
			for (int i = block - 1; i >= 0; i--)
				if(DP[v][i].first != -1 && !bad[DP[v][i].first])
					ans = DP[v][i].second;
			cout << ans << "\n";
		}
		for (int i = 0; i < t; i++)
			bad[input[i]] = 0;
	}
}

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