oj.uz

답안 #153239

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
153239 2019-09-13T01:59:24 Z gs18103 먼 별 (KOI16_dist) C++14
2 / 100
 212 ms 3416 KB 
#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
 
using namespace std;
typedef long long ll;
typedef pair <ll, ll> pll;
 
ll arr[30303][4];
pll base;
int n, T;

ll ccw(pll a, pll b, pll c) {
	return (b.x-a.x)*(c.y-a.y)-(b.y-a.y)*(c.x-a.x);
}

ll dis(pll a, pll b) {
	return (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);
}

ll cal_dis(int t) {
	vector <pll> p, ch;
	for(int i = 0; i < n; i++) {
		p.emplace_back(arr[i][0] + arr[i][2] * (ll)t, arr[i][1] + arr[i][3] * (ll)t);
	}
	sort(all(p));
	p.erase(unique(all(p)), p.end());
	if(p.size() == 1) return 0;
	base = p[0];
	sort(p.begin()+1, p.end(), [](pll a, pll b) {
		if(ccw(base, a, b) == 0) return dis(base, a) > dis(base, b);
		return ccw(base, a, b) > 0;
	});
	ch.push_back(base);
	for(int i = 1; i < p.size(); i++) {
		while(ch.size() >= 2) {
			pll p1 = ch[ch.size()-2], p2 = ch[ch.size()-1];
			if(ccw(p1, p2, p[i]) > 0) break;
			ch.pop_back();
		}
		ch.push_back(p[i]);
	}

	ll ret = 0;
	for(int i = 0; i < ch.size(); i++) {
		if(i+1 < ch.size() && ch[i+1].x < ch[i].x) break;
		int lb = i, ub = ch.size()-1;
		while(lb + 10 < ub) {
			int m1 = (2 * lb + ub) / 3, m2 = (lb + 2 * ub) / 3;
			if(dis(ch[m1], ch[i]) > dis(ch[m2], ch[i])) ub = m2;
			else lb = m1;
		}
		for(int j = lb; j <= ub; j++) {
			if(dis(ch[i], ch[lb]) < dis(ch[i], ch[j])) lb = j;
		}
		ret = max(ret, dis(ch[i], ch[lb]));
	}
	return ret;
}

int search(int s, int e) {
	if(s + 10 >= e) 	{
		ll dis = 9000000000000000000LL;
		for(int i = s; i <= e; i++) {
			dis = min(dis, cal_dis(i));
		}
		for(int i = s; i <= e; i++) {
			if(dis == cal_dis(i)) return i;
		}
	}
	int t1 = (2 * s + e) / 3, t2 = (s + 2 * e) / 3;
	ll dis1 = cal_dis(t1), dis2 = cal_dis(t2);
	if(dis1 <= dis2) return search(s, t2);
	else return search(t1, e);
}
 
int main() {
	ios::sync_with_stdio(false); cin.tie(0);
	cin >> n >> T;
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < 4; j++) {
			cin >> arr[i][j];
		}
	}
	int ans = search(0, T);
	cout << ans << endl << cal_dis(ans);
}

Compilation message

dist.cpp: In function 'll cal_dis(int)':
dist.cpp:36:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 1; i < p.size(); i++) {
                 ~~^~~~~~~~~~
dist.cpp:46:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < ch.size(); i++) {
                 ~~^~~~~~~~~~~
dist.cpp:47:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i+1 < ch.size() && ch[i+1].x < ch[i].x) break;
      ~~~~^~~~~~~~~~~

Subtask #1
2.0 / 2.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 380 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 436 KB Output is correct
9 Correct 3 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct

Subtask #2
0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 380 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 436 KB Output is correct
9 Correct 3 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 17 ms 504 KB Output is correct
12 Correct 16 ms 376 KB Output is correct
13 Correct 14 ms 476 KB Output is correct
14 Correct 18 ms 504 KB Output is correct
15 Incorrect 11 ms 376 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #3
0 / 39.0

# 결과 실행 시간 메모리 Grader output
1 Correct 212 ms 3012 KB Output is correct
2 Correct 157 ms 2840 KB Output is correct
3 Correct 164 ms 2868 KB Output is correct
4 Correct 146 ms 3416 KB Output is correct
5 Incorrect 88 ms 3012 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 19.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 380 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 436 KB Output is correct
9 Correct 3 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 17 ms 504 KB Output is correct
12 Correct 16 ms 376 KB Output is correct
13 Correct 14 ms 476 KB Output is correct
14 Correct 18 ms 504 KB Output is correct
15 Incorrect 11 ms 376 KB Output isn't correct
16 Halted 0 ms 0 KB -