Submission #1189017

#	Time	Username	Problem	Language	Result	Execution time	Memory
1189017		alexdd	Collapse (JOI18_collapse)	C++20	0 / 100	243 ms	26044 KiB

collapse

#include "collapse.h"
#include<bits/stdc++.h>
using namespace std;
int n;

const int BUC = 320;

struct DSU
{
	int father[100005],siz[100005];
	vector<pair<pair<int,int>,int>> history;
	void init()
	{
		history.clear();
		for(int i=0;i<n;i++)
			father[i]=i, siz[i]=1;
	}
	int gas(int x)
	{
		if(father[x]!=x)
			return gas(father[x]);
		return x;
	}
	void unite(int x, int y)
	{
		x = gas(x);
		y = gas(y);
		if(x==y)
			return;
		history.push_back({{y,father[y]},0});
		history.push_back({{x,siz[x]},1});
		father[y] = x;
		siz[x] += siz[y];
	}
	int get_time()
	{
		return history.size();
	}
	void rollback(int t)
	{
		while((int)history.size() > t)
		{
			if(history.back().second == 0)
				father[history.back().first.first] = history.back().first.second;
			else
				siz[history.back().first.first] = history.back().first.second;
			history.pop_back();
		}
	}
};

vector<pair<int,int>> begin_on_t[100005],end_on_t[100005];
vector<pair<int,pair<int,int>>> begin_on_poz[100005],end_on_poz[100005];

vector<pair<pair<int,int>,pair<int,int>>> edges;

void add_edge(int tle, int tri, int x, int y)
{
	assert(tle<=tri);
	assert(x<=y);

	edges.push_back({{tle,tri},{x,y}});

	begin_on_t[tle].push_back({x,y});
	end_on_t[tri].push_back({x,y});
	begin_on_poz[x].push_back({y,{tle,tri}});
	end_on_poz[y].push_back({x,{tle,tri}});
}

vector<pair<pair<int,int>,int>> qrys[100005];

bool cmp_edge(pair<pair<int,int>,pair<int,int>> x, pair<pair<int,int>,pair<int,int>> y)
{
	return x.second.second < y.second.second;
}
bool cmp_edge2(pair<pair<int,int>,pair<int,int>> x, pair<pair<int,int>,pair<int,int>> y)
{
	return x.second.first > y.second.first;
}
bool cmp_qry(pair<pair<int,int>,int> x, pair<pair<int,int>,int> y)
{
	return x.first.second < y.first.second;
}

vector<int> sol;
void solve()
{
	sort(edges.begin(),edges.end(),cmp_edge);
	for(int b=0;b<=n/BUC;b++)
	{
		DSU dsu;
		dsu.init();
		int ble = b*BUC, bri = (b+1)*BUC - 1;
		sort(qrys[b].begin(),qrys[b].end(),cmp_qry);
		vector<pair<pair<int,int>,pair<int,int>>> base_edges,special_edges;
		for(auto [t,e]:edges)
		{
			if(t.first <= ble && bri <= t.second)
				base_edges.push_back({t,e});
			else
				special_edges.push_back({t,e});
		}
		int poz_base=0;
		for(auto [q,id]:qrys[b])
		{
			int w = q.first, p = q.second;
			while(poz_base < base_edges.size() && base_edges[poz_base].second.second <= p)
			{
				dsu.unite(base_edges[poz_base].second.first, base_edges[poz_base].second.second);
				poz_base++;
			}

			int old_t = dsu.get_time();
			for(auto [t,e]:special_edges)
				if(t.first <= w && w <= t.second && e.second <= p)
					dsu.unite(e.first, e.second);

			sol[id] += dsu.get_time()/2;

			dsu.rollback(old_t);
		}
	}
	
	sort(edges.begin(),edges.end(),cmp_edge2);///------------------------------------
	for(int b=0;b<=n/BUC;b++)
	{
		for(auto [q,id]:qrys[b])
		{
			int w = q.first, p = q.second;

			DSU dsu;
			dsu.init();

			for(auto [t,e]:edges)
				if(t.first <= w && w <= t.second && e.first > p)
					dsu.unite(e.first, e.second);

			sol[id] += dsu.get_time()/2;
		}
	}
}

std::vector<int> simulateCollapse(
	int N,
	std::vector<int> T,
	std::vector<int> X,
	std::vector<int> Y,
	std::vector<int> W,
	std::vector<int> P)
{
	n=N;
	map<pair<int,int>,int> construction_day;
	for(int i=0;i<T.size();i++)
	{
		if(X[i] > Y[i])
			swap(X[i],Y[i]);
		if(T[i]==0)
		{
			construction_day[{X[i],Y[i]}] = i;
		}
		else
		{
			add_edge(construction_day[{X[i],Y[i]}],i-1,X[i],Y[i]);
			construction_day[{X[i],Y[i]}] = -1;
		}
	}
	for(auto it:construction_day)
	{
		if(it.second != -1)
		{
			add_edge(it.second, (int)T.size() + 2, it.first.first, it.first.second);
		}
	}

	for(int i=0;i<W.size();i++)
		qrys[W[i]/BUC].push_back({{W[i],P[i]},i});
	sol.resize((int)W.size(),0);

	solve();

	for(int i=0;i<W.size();i++)
		sol[i] = n - sol[i];
	return sol;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 30
• Subtask 3: 0 / 30
• Subtask 4: 0 / 35