제출 #1184658

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1184658		kl0989e	Joker (BOI20_joker)	C++17	100 / 100	347 ms	16624 KiB

Joker

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define vl vector<ll>
#define pi pair<int, int>
#define pl pair<ll,ll>
#define all(x) (x).begin(),(x).end()

const int maxn=2e5+10;

vector<pi> edges(maxn);
vi nums(maxn,maxn);

vi head(maxn);
vi flip(maxn,0);
vi sze(maxn,1);
vector<vi> changes;

int m;

bool ok=1;

pi get(int a) {
	if (a==head[a]) {
		return {a,0};
	}
	pi temp=get(head[a]);
	return {temp.fi,temp.se^flip[a]};
}

void unite(int a, int b) {
	int f1,f2;
	tie(a,f1)=get(a);
	tie(b,f2)=get(b);
	if (a==b) {
		if (f1==f2 && ok) {
			changes.pb({1});
			ok=0;
		}
		return;
	}
	if (sze[a]<sze[b]) {
		swap(a,b);
		swap(f1,f2);
	}
	changes.pb({b,head[b],flip[b],a,sze[a]});
	head[b]=a;
	flip[b]=f1^f2^1;
	sze[a]=max(sze[a],sze[b]+1);
}

void rollback(int a) {
	while (changes.size()>a) {
		if (changes.back().size()==1) {
			ok=1;
		}
		else {
			head[changes.back()[0]]=changes.back()[1];
			flip[changes.back()[0]]=changes.back()[2];
			sze[changes.back()[3]]=changes.back()[4];
		}
		changes.pop_back();
	}
}

void dfs(int l, int r, int tl, int tr) {
	if (tr<tl) {
		return;
	}
	int sze=changes.size();
	int tm=tl+(tr-tl)/2;
	int ttl=l,ttr=r,tttr=r;
	while (l<tm) {
		unite(edges[l].fi,edges[l].se);
		l++;
	}
	while (r>=l && ok) {
		unite(edges[r].fi,edges[r].se);
		r--;
	}
	nums[tm]=r;
	rollback(sze);
	while (ttr>r) {
		unite(edges[ttr].fi,edges[ttr].se);
		ttr--;
	}
	dfs(ttl,ttr,tl,tm-1);
	rollback(sze);
	while (ttl<l) {
		unite(edges[ttl].fi,edges[ttl].se);
		ttl++;
	}
	dfs(ttl,tttr,tm+1,tr);
	rollback(sze);
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
	iota(all(head),0);
	int n,m,q;
	cin >> n >> m >> q;
	for (int i=0; i<m; i++) {
		cin >> edges[i].fi >> edges[i].se;
		edges[i].fi--;
		edges[i].se--;
	}
	dfs(0,m-1,0,m-1);
	int a,b;
	for (int i=0; i<q; i++) {
		cin >> a >> b;
		a--;
		b--;
		if (b<=nums[a]) {
			cout << "YES\n";
		}
		else {
			cout << "NO\n";
		}
	}
    return 0;
}

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