제출 #438680

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
438680		soroush	Joker (BOI20_joker)	C++17	39 / 100	146 ms	10968 KiB

Joker

#include <bits/stdc++.h>

using namespace std;

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

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 2e5+10;
const ll mod = 1e9+7;

#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}

int n, m, q;
int a[maxn], b[maxn], l[maxn], r[maxn];
int par[maxn], sz[maxn];
bool val[maxn];

int getpar(int v){
	return ((~par[v]) ? getpar(par[v]) : v);
}

bool getval(int v){
	return ((~par[v]) ? val[v] ^ getval(par[v]) : val[v]);
}

bool merge(int v, int u){
	int pu = getpar(u) , pv = getpar(v);
	if(pu == pv)
		return getval(u) == getval(v);
	if(sz[pu] > sz[pv])swap(pu , pv);
	val[pu] ^= getval(v) == getval(u);
	par[pu] = pv;
	sz[pv] += sz[pu];
	return 0;
}

bool solve(int l , int r){
	for(int i = 0 ; i < l ; i ++){
		if(merge(a[i], b[i])){
			if(i > n){
				for(int j = 0 ; j < n ; j ++)
					par[j] = -1, val[j] = 0, sz[j] = 1;
			}
			else{
				for(int j = 0; j <= i ; j ++)
					par[a[j]] = par[b[j]] = -1 , val[a[j]] = val[b[j]] = 0 , sz[a[j]] = sz[b[j]] = 1;
			}
			return 1;
		}
	}
	for(int i = r ; i < m ; i ++){
		if(merge(a[i], b[i])){
			if(l + i - r > n){
				for(int j = 0 ; j < n ; j ++)
					par[j] = -1, val[j] = 0 , sz[j] = 1;
			}
			else{
				for(int j = 0; j < l ; j ++)
					par[a[j]] = par[b[j]] = -1 , val[a[j]] = val[b[j]] = 0 , sz[a[j]] = sz[b[j]] = 1;
				for(int j = r ; j <= i ; j ++)
					par[a[j]] = par[b[j]] = -1 , val[a[j]] = val[b[j]] = 0 , sz[a[j]] = sz[b[j]] = 1;
			}
			return 1;
		}
	}
	if(m - r - l < n){
		for(int j = 0; j < l ; j ++)
			par[a[j]] = par[b[j]] = -1 , val[a[j]] = val[b[j]] = 0 , sz[a[j]] = sz[b[j]] = 1;
		for(int j = r ; j < m ; j ++)
			par[a[j]] = par[b[j]] = -1 , val[a[j]] = val[b[j]] = 0 , sz[a[j]] = sz[b[j]] = 1;
	}
	else{
		for(int j = 0 ; j < n ; j ++)
			par[j] = -1, val[j] = 0 , sz[j] = 1;
	}
	return 0;
}

bool sub3 = 0;
int srt[maxn];
bool ans[maxn];

int32_t main(){
	ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	cin >> n >> m >> q;
	ms(par, -1);
	for(int i = 0 ; i < m ; i ++)
		cin >> a[i] >> b[i] , a[i] -- , b[i] --;
	for(int i = 0 ; i < n ; i ++)sz[i] = 1;
	for(int i = 0 ; i < q ; i ++)
		cin >> l[i] >> r[i], l[i] --, sub3 |= l[i];
	if(n <= 2000 and m <= 2000 and q <= 2000){
		for(int i = 0 ; i < q ; i ++)
			cout << (solve(l[i] , r[i]) ? "YES" : "NO") << endl;
		return 0;
	}
	if(!sub3){
		for(int i = 0 ; i < q ; i ++)
			srt[i] = i;
		sort(srt , srt + q , [](int i, int j){return r[i] > r[j];});
		bool cur = 0;
		int pos = m-1;
		for(int i = 0 ; i < q ; i ++){
			while(pos >= r[srt[i]]){
				cur |= merge(a[pos], b[pos]);
				pos --;
			}
			ans[srt[i]] = cur;
		}
		for(int i = 0 ; i < q ; i ++)
			cout << ((ans[i]) ? "YES" : "NO") << endl;
		return 0;
	}
	return(0);
}

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