Submission #527126

#	Time	Username	Problem	Language	Result	Execution time	Memory
527126		Leonardo_Paes	Strange Device (APIO19_strange_device)	C++17	35 / 100	737 ms	78896 KiB

strange_device

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pii;
#define f first
#define s second
// number x and x + (a / gcd(a, b+1) * b) are equal

ll gcd(ll a, ll b){
	if(b == 0) return a;
	return gcd(b, a%b);
}

bool overflow(ll a, ll b){
	ll v = a*b;
	if(a == v/b) return true;
	return false;
}

const ll inf = 1e18;

int main(){
	ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
	int n;
	ll a, b;
	cin >> n >> a >> b;
	ll aux = a / (gcd(a, b+1));
	bool ok = overflow(aux, b);	
	ll m = (ok ? aux * b : inf + 1);
	vector<pii> v;
	bool mx = 0;
	for(int i=0; i<n; i++){
		ll l, r;
		cin >> l >> r;
		if(r-l+1 > m) mx = 1;
		l = l % m, r = r % m;
		if(n == 1){
			if(mx) cout << m << "\n";
			else cout << r-l+1 << "\n";
			return 0;
		}
		if(l <= r){
			v.push_back({l, r});
			v.push_back({r, inf + 5});
		}
		else{
			v.push_back({l, m-1});
			v.push_back({m-1, inf + 5});
			v.push_back({0, r});
			v.push_back({r, inf + 5});
		}
	}
	if(mx){
		cout << m << "\n";
		return 0;
	}
	multiset<ll> s;
	ll ans = 0;
	sort(v.begin(), v.end());
	for(pii x : v){
		ll l = x.f, r = x.s;
		//cout << l << " " << r << "\n";
		if(r == inf + 5){ // out
			s.erase(s.find(-l));
		}
		else{ // in
			if(s.empty()) ans += r-l+1;
			else{
				ll mxx = -(*s.begin());
				ans += max(0LL, r-mxx);
			}
			s.insert(-r);
		}
	}
	cout << ans << "\n";
	return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 20 / 20
• Subtask 7: 0 / 20
• Subtask 8: 0 / 30