Submission #944449

#	Time	Username	Problem	Language	Result	Execution time	Memory
944449		daoquanglinh2007	Nicelines (RMI20_nicelines)	C++17	77.76 / 100	50 ms	936 KiB

nicelines

#include <bits/stdc++.h>
#include "nice_lines.h"
using namespace std;
 
#define ll long long
#define ld long double
#define pii pair <int, int>
#define pld pair <ld, ld>
#define fi first
#define se second
#define mp make_pair
 
const ll LIM = 1e4, MAX_DEP = 32;

const ld EPS = 1e-9, inf = 1e18;

struct line{
	ld a, b, c;
};

ll x0 = 2*LIM+10;
vector <int> va, vb;
vector <ld> pos, neg;
set <pii> S;
 
void get(ld y){
	int b = int(round(y+x0*LIM+LIM))%x0-LIM, a = int(round(y-b)/(ld)x0);
	if (!S.count(mp(a, b))){
		va.push_back(a);
		vb.push_back(b);
		S.insert(mp(a, b));
		if (x0 > 0) pos.push_back(y); else neg.push_back(y);
	}
}
 
void dnc(int dep, ld l, ld r, ld fl, ld fr){
	if (dep == MAX_DEP){
		get((l+r)/2.0);
		return;
	}
	ld mid = (l+r)/2.0;
	if (fl == +inf) fl = query(x0, l);
	if (fr == +inf) fr = query(x0, r);
	ld fmid = query(x0, mid);
	if (abs(2.0*fmid - (fl+fr)) <= EPS) return;
	dnc(dep+1, l, mid, fl, fmid);
	dnc(dep+1, mid, r, fmid, fr);
}

line calc(pld A, pld B){
	line d;
	d.a = A.se-B.se, d.b = B.fi-A.fi, d.c = -A.fi*(A.se-B.se)-A.se*(B.fi-A.fi);
	return d;
}
 
void solve(int subtask_id, int N){
	va.clear();
	vb.clear();
	dnc(0, -2*LIM*(x0+1), 2*LIM*(x0+1), +inf, +inf);
	if (N <= 3){
		x0 = -x0;
		dnc(0, -2*LIM*(-x0+1), 2*LIM*(-x0+1), +inf, +inf);
		va.clear(); vb.clear();
		assert((int)pos.size() == N);
		assert((int)neg.size() == N);
		sort(pos.begin(), pos.end(), greater <ld>());
		sort(neg.begin(), neg.end());
		for (int i = 0; i < N; i++){
			line d = calc(mp(-x0, pos[i]), mp(x0, neg[i]));
			int a = round(-d.a/d.b), b = round(-d.c/d.b);
			va.push_back(a);
			vb.push_back(b);
		}
	}
	the_lines_are(va, vb);
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 0 / 7
• Subtask 4: 14.1625026041 / 19
• Subtask 5: 21.1162429669 / 23
• Subtask 6: 18.4794436341 / 27