Submission #388859

#	Time	Username	Problem	Language	Result	Execution time	Memory
388859		huangqr	Joker (BOI20_joker)	C++14	49 / 100	2075 ms	42956 KiB

Joker

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pl;
typedef pair<ll,pl> ppl;
const ll lim=2e5+5;
ll par[lim],rnk[lim],rel[lim];
ll parcpy[lim],rnkcpy[lim],relcpy[lim];
 
struct xystate{
	ll x,parx,relx,rnkx;
	ll y,pary,rely,rnky;
	xystate(ll ix,ll iparx,ll irelx,ll irnkx,
	ll iy,ll ipary,ll irely,ll irnky){
		x=ix,parx=iparx,relx=irelx,rnkx=irnkx;
		y=iy,pary=ipary,rely=irely,rnky=irnky;
	}
};

vector<xystate>sv;
 
pl findset(ll par[],ll rel[],ll x){
	ll cur=0,og=x;
	while(x!=par[x]){
		if(rel[x])cur=1-cur;
		x=par[x];
	}
//	par[og]=x;
//	rel[og]=cur;
	return {x,cur};
}
 
void mergeset(ll par[],ll rnk[],ll rel[],ll x,ll y){
	pl px=findset(par,rel,x),py=findset(par,rel,y);
	x=px.first,y=py.first;
	if(x==y)return;
	if(rnk[x]>rnk[y])swap(x,y);
	sv.push_back(xystate(x,par[x],rel[x],rnk[x],y,par[y],rel[y],rnk[y]));
	if(rnk[x]==rnk[y])rnk[y]++;
	par[x]=y;
	rnk[y]++;
	rel[x]=(px.second==py.second);
	return;
}

void rollback(ll until_sz){
	while(sv.size()>until_sz){
		xystate c=sv.back();
		par[c.x]=c.parx;
		rnk[c.x]=c.rnkx;
		rel[c.x]=c.relx;
		par[c.y]=c.pary;
		rnk[c.y]=c.rnky;
		rel[c.y]=c.rely;
		sv.pop_back();
	}
}
 
int main(){
	ios_base::sync_with_stdio(0),cin.tie(NULL);
	ll n,m,q;
	cin>>n>>m>>q;
	for(int i=1;i<=n;i++)par[i]=i;
	vector<pl>v;
	vector<pl>qs[lim];
	for(int i=0;i<m;i++){
		ll a,b;
		cin>>a>>b;
		v.emplace_back(a,b);
	}	
	//v.emplace_back(0,0);
	bool ans[lim],cfa=0;
	fill(ans,ans+lim,0);
	for(int i=0;i<q;i++){
		ll a,b;
		cin>>a>>b;
		b--,b++;//b is the minimum index that can be used on the right side
		qs[b].emplace_back(a,i);
	}
	for(int i=m;i>=m;i--){
		sort(qs[i].begin(),qs[i].end());
		for(int i=1;i<=n;i++)parcpy[i]=par[i],rnkcpy[i]=rnk[i],relcpy[i]=rel[i];
		ll cur=0;
		bool oddc=0;
		for(auto x:qs[i]){
			if(oddc==1){
				ans[x.second]=1;
				continue;
			}
			for(;cur+1<x.first;cur++){
				pl x=findset(parcpy,relcpy,v[cur].first),y=findset(parcpy,relcpy,v[cur].second);
				if(x.first==y.first){
				if(x.second==y.second){
					oddc=1;
				}
			}
				else mergeset(parcpy,rnkcpy,relcpy,v[cur].first,v[cur].second);
			}
			ans[x.second]=oddc;
			
		}
	}
	
	for(int i=m-1;i>=1;i--){
		if(cfa==1){
			for(auto x:qs[i])ans[x.second]=1;
			continue;
		}
		pl x=findset(par,rel,v[i].first),y=findset(par,rel,v[i].second);
		if(x.first==y.first){
			if(x.second==y.second){
				cfa=1;
			}
		}
		else mergeset(par,rnk,rel,v[i].first,v[i].second);
 
		if(qs[i].empty())continue;
		if(cfa==1){
			for(auto x:qs[i])ans[x.second]=1;
			continue;
		}
		
		sort(qs[i].begin(),qs[i].end());
		//for(int i=1;i<=n;i++)parcpy[i]=par[i],rnkcpy[i]=rnk[i],relcpy[i]=rel[i];
		ll cur=0,prevsz=sv.size();
		bool oddc=0;
		for(auto x:qs[i]){
			if(oddc==1){
				ans[x.second]=1;
				continue;
			}
			for(;cur+1<x.first;cur++){
				pl x=findset(par,rel,v[cur].first),y=findset(par,rel,v[cur].second);
				if(x.first==y.first){
					if(x.second==y.second){
						oddc=1;
					}
				}
				else mergeset(par,rnk,rel,v[cur].first,v[cur].second);
			}
			ans[x.second]=oddc;
			
		}
		rollback(prevsz);
	}
	for(int i=0;i<q;i++){
		if(ans[i])cout<<"YES\n";
		else cout<<"NO\n";
	}
	return 0;
}

Compilation message (stderr)

Joker.cpp: In function 'pl findset(ll*, ll*, ll)':
Joker.cpp:23:11: warning: unused variable 'og' [-Wunused-variable]
   23 |  ll cur=0,og=x;
      |           ^~
Joker.cpp: In function 'void rollback(ll)':
Joker.cpp:47:17: warning: comparison of integer expressions of different signedness: 'std::vector<xystate>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   47 |  while(sv.size()>until_sz){
      |        ~~~~~~~~~^~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 8 / 8
• Subtask 3: 25 / 25
• Subtask 4: 10 / 10
• Subtask 5: 0 / 22
• Subtask 6: 0 / 29