oj.uz

답안 #98852

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
98852 2019-02-26T16:34:17 Z jhnah917 먼 별 (KOI16_dist) C++14
100 / 100
 452 ms 3648 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<ll, ll> p;

struct Star{
	ll x, y, dx, dy;
	void get(){
		cin >> x >> y >> dx >> dy;
	}
};

int n, t;
vector<Star> v;
vector<p> arr;

int ccw(p a, p b, p c){
	ll res = (a.first*b.second) + (b.first*c.second) + (c.first*a.second);
	res -= (b.first*a.second) + (c.first*b.second) + (a.first*c.second);
	if(res > 0) return 1;
	if(res) return -1;
	return 0;
}

ll dist(p a, p b){
	ll dx = a.first - b.first;
	ll dy = a.second - b.second;
	return dx*dx + dy*dy;
}

bool chk(p s, p e, p ss, p ee){
	return ccw({0, 0}, {e.first-s.first, e.second-s.second}, {ee.first-ss.first, ee.second-ss.second}) >= 0;
}

ll f(int t){
	for(int i=0; i<n; i++){
		arr[i] = {v[i].x + v[i].dx * t, v[i].y + v[i].dy * t};
	}
	swap(arr[0], *min_element(arr.begin(), arr.end()));
	sort(arr.begin()+1, arr.end(), [](const p a, const p b){
		int cw = ccw(arr[0], a, b);
		if(cw) return cw > 0;
		return dist(arr[0], a) < dist(arr[0], b);
	});
	
	vector<p> hull;
	for(int i=0; i<n; i++){
		while(hull.size() >= 2 && ccw(hull[hull.size()-2], hull.back(), arr[i]) <= 0){
			hull.pop_back();
		}
		hull.push_back(arr[i]);
	}
	
	ll ret = 0;
	int p = 0;
	for(int i=0; i<hull.size(); i++){
		while(p+1 < hull.size() && chk(hull[i], hull[i+1], hull[p], hull[p+1])){
			ret = max(ret, dist(hull[i], hull[p])); p++;
		}
		ret = max(ret, dist(hull[i], hull[p]));
	}
	return ret;
}

int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin >> n >> t;
	v.resize(n); arr.resize(n);
	for(int i=0; i<n; i++) v[i].get();
	ll s = 0, e = t;
	while(s+3 <= e){
		ll l = (s+s+e)/3, r = (s+e+e)/3;
		ll t1 = f(l), t2 = f(r);
		if(t1 > t2) s = l;
		else e = r;
	}
	ll ans = 1e18;
	int idx = s;
	for(ll i=s; i<=e; i++){
		ll now = f(i);
		if(ans > now){
			ans = now, idx = i;
		}
	}
	cout << idx << "\n" << ans;
}

Compilation message

dist.cpp: In function 'll f(int)':
dist.cpp:57:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<hull.size(); i++){
               ~^~~~~~~~~~~~
dist.cpp:58:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(p+1 < hull.size() && chk(hull[i], hull[i+1], hull[p], hull[p+1])){
         ~~~~^~~~~~~~~~~~~

Subtask #1
2.0 / 2.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 3 ms 384 KB Output is correct
4 Correct 3 ms 384 KB Output is correct
5 Correct 3 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 2 ms 356 KB Output is correct
10 Correct 2 ms 384 KB Output is correct

Subtask #2
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 3 ms 384 KB Output is correct
4 Correct 3 ms 384 KB Output is correct
5 Correct 3 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 2 ms 356 KB Output is correct
10 Correct 2 ms 384 KB Output is correct
11 Correct 10 ms 512 KB Output is correct
12 Correct 13 ms 512 KB Output is correct
13 Correct 9 ms 384 KB Output is correct
14 Correct 13 ms 384 KB Output is correct
15 Correct 12 ms 384 KB Output is correct
16 Correct 19 ms 512 KB Output is correct
17 Correct 14 ms 384 KB Output is correct
18 Correct 10 ms 356 KB Output is correct
19 Correct 8 ms 384 KB Output is correct
20 Correct 11 ms 384 KB Output is correct

Subtask #3
39.0 / 39.0

# 결과 실행 시간 메모리 Grader output
1 Correct 94 ms 2636 KB Output is correct
2 Correct 96 ms 2484 KB Output is correct
3 Correct 84 ms 2304 KB Output is correct
4 Correct 83 ms 3476 KB Output is correct
5 Correct 108 ms 2488 KB Output is correct
6 Correct 143 ms 3404 KB Output is correct
7 Correct 68 ms 2296 KB Output is correct
8 Correct 47 ms 2048 KB Output is correct
9 Correct 71 ms 3536 KB Output is correct
10 Correct 81 ms 2432 KB Output is correct

Subtask #4
19.0 / 19.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 3 ms 384 KB Output is correct
4 Correct 3 ms 384 KB Output is correct
5 Correct 3 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 2 ms 356 KB Output is correct
10 Correct 2 ms 384 KB Output is correct
11 Correct 10 ms 512 KB Output is correct
12 Correct 13 ms 512 KB Output is correct
13 Correct 9 ms 384 KB Output is correct
14 Correct 13 ms 384 KB Output is correct
15 Correct 12 ms 384 KB Output is correct
16 Correct 19 ms 512 KB Output is correct
17 Correct 14 ms 384 KB Output is correct
18 Correct 10 ms 356 KB Output is correct
19 Correct 8 ms 384 KB Output is correct
20 Correct 11 ms 384 KB Output is correct
21 Correct 94 ms 2636 KB Output is correct
22 Correct 96 ms 2484 KB Output is correct
23 Correct 84 ms 2304 KB Output is correct
24 Correct 83 ms 3476 KB Output is correct
25 Correct 108 ms 2488 KB Output is correct
26 Correct 143 ms 3404 KB Output is correct
27 Correct 68 ms 2296 KB Output is correct
28 Correct 47 ms 2048 KB Output is correct
29 Correct 71 ms 3536 KB Output is correct
30 Correct 81 ms 2432 KB Output is correct
31 Correct 364 ms 2516 KB Output is correct
32 Correct 387 ms 2424 KB Output is correct
33 Correct 381 ms 2424 KB Output is correct
34 Correct 406 ms 2680 KB Output is correct
35 Correct 452 ms 2556 KB Output is correct
36 Correct 373 ms 3460 KB Output is correct
37 Correct 362 ms 2432 KB Output is correct
38 Correct 247 ms 2680 KB Output is correct
39 Correct 297 ms 2552 KB Output is correct
40 Correct 369 ms 2552 KB Output is correct
41 Correct 405 ms 3496 KB Output is correct
42 Correct 355 ms 3648 KB Output is correct