Submission #670806

#	Time	Username	Problem	Language	Result	Execution time	Memory
670806		thiago_bastos	Wish (LMIO19_noras)	C++17	100 / 100	480 ms	25368 KiB

noras

#include "bits/stdc++.h"

using namespace std;

#define INF 1000000000
#define INFLL 1000000000000000000ll
#define EPS 1e-9
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define pb push_back
#define fi first
#define sc second

using i64 = long long;
using u64 = unsigned long long;
using ld = long double;
using ii = pair<int, int>;

int n, radius;

bool getSecs(int a, int b, int c, int d, ld& s1, ld& s2) {
	i64 C = (i64)a * a + (i64)b * b - (i64)radius * radius;
	i64 B = 2 * ((i64)a * c + (i64)b * d);
	i64 A = (i64)c * c + (i64)d * d;
	__int128 D = (__int128)B * B - (__int128)4 * A * C;
	if(D < 0) return false;
	ld delta = sqrt((ld)D);
	s1 = (-B - delta) / (2.0L * A);
	s2 = (-B + delta) / (2.0L * A); 
	return true;
}

void solve() {
	cin >> n >> radius;

	set<pair<i64, int>> sweep;
	int opening = 0, ans = 0;

	for(int i = 1; i <= n; ++i) {
		int a, b, c, d;
		ld s1, s2;

		cin >> a >> b >> c >> d;

		if(!getSecs(a, b, c - a, d - b, s1, s2)) continue;
		
		i64 l = max(0.0L, ceil(s1)), r = floor(s2); 
		
		if(l > r) continue;

		sweep.emplace(l, -i);
		sweep.emplace(r, i);
	}

	for(auto [x, k] : sweep) {
		opening += k < 0 ? 1 : -1;
		ans = max(ans, opening);
	}

	cout << ans << '\n';
}

int main() {
	ios_base :: sync_with_stdio(false);
	cin.tie(0);
	int t = 1;
	//cin >> t;
	while(t--) solve();
	return 0;
}

• Subtask 1: 23 / 23
• Subtask 2: 23 / 23
• Subtask 3: 15 / 15
• Subtask 4: 32 / 32
• Subtask 5: 7 / 7