Submission #926746

#	Time	Username	Problem	Language	Result	Execution time	Memory
926746		mansur	Joker (BOI20_joker)	C++17	100 / 100	203 ms	33988 KiB

Joker

#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
//#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
 
#include<bits/stdc++.h>	
 
using namespace std;
 
#define all(a) a.begin(), a.end()                                                   
#define rall(a) a.rbegin(), a.rend()                 
#define sz(a) (int)a.size()
#define s second
#define f first
 
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
 
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
     
vector<pii> rid = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
vector<pii> dir = {{-1, -1}, {-1, 1}, {1, -1}, {1, 1}};
 
const int N = 1e6 + 1, mod = 998244353;
 
const ll inf = 1e9;
 
double eps = 1e-15;
                                                
bool flg = 0;
 
bool ok = 1, was[N];
vector<pii> g(N);
 
int p[N], pr[N];
int sz[N], pt[N];
vector<pii> h;
 
pii get(int x) {
 	if (p[x] == x) return {x, 0};
 	pii val = get(p[x]);
 	return {val.f, ((pr[x] + val.s) & 1)};
}
 
inline void add(int id) {
	int u = g[id].f;
	int v = g[id].s;
	if (u == -1) return;
	pii x = get(u);
	pii y = get(v);
	if (x.f == y.f) {
		if (x.s == y.s) {
			if (ok) {
			    h.push_back({-1, -1});
				ok = 0;
			}    
		}
		return;
	}
	if (sz[x.f] > sz[y.f]) swap(x, y);
	h.push_back({x.f, sz[x.f]});
	h.push_back({y.f, sz[y.f]});
	p[x.f] = y.f;
	pr[x.f] = ((x.s + y.s + 1) & 1);  	
	sz[y.f] += sz[x.f];
}
 
inline void rb() {
	while (sz(h) && !pt[sz(h)]) {
		pii x = h.back();
		h.pop_back();
		if (x.f == -1) {
			ok = 1;
			continue;
		}
		p[x.f] = x.f;
		pr[x.f] = 0;
		sz[x.f] = x.s;
	}
	pt[sz(h)]--; 
}
 
int ps[N];
 
void f(int l, int r, int tr) {
	if (l > r) return;
	int m = (l + r) / 2;
	pt[sz(h)]++;
	for (int i = m - 1; i >= l; i--) 
		add(i);
	pt[sz(h)]++;
	for (int i = tr; i >= m; i--) {
		add(i);
		if (!ok) {
			ps[m] = i;
			break;
		}
	}
	rb();
	add(m);
	f(m + 1, r, tr);
	rb();
	if (!ps[m]) return;
	pt[sz(h)]++;
	for (int i = tr; i > ps[m]; i--)
		add(i);
	f(l, m - 1, ps[m]);
	rb();
}
 
void slv() {
	int n, m, q;
	cin >> n >> m >> q;
	for (int i = 1; i <= m; i++) {
		int u, v;
		cin >> u >> v;
		g[i] = {u, v};
	}
	g[m + 1] = {-1, -1};
	for (int i = 1; i <= n; i++) 
		p[i] = i, sz[i] = 1;
	f(1, m, m + 1);
	for (int i = 1; i <= q; i++) {
		int l, r;
		cin >> l >> r;
		l = max(l, 1);
		r = min(r, m);
		if (ps[l] > r) cout << "YES\n";
		else cout << "NO\n";
	}
}                                                                           
 
main() {
	ios_base::sync_with_stdio(0);	                                                                                       
	cin.tie(0);
	int tp = 1;
	if (flg) cin >> tp;
	while (tp--) {  	
		slv();
	}
}

Compilation message (stderr)

Joker.cpp:132:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  132 | main() {
      | ^~~~

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