Submission #153199

# Submission time Handle Problem Language Result Execution time Memory
153199 2019-09-12T21:08:52 Z gs18103 None (KOI16_dist) C++14
2 / 100
2000 ms 2720 KB
#include <bits/stdc++.h>
#define x first
#define y second
 
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] * t, arr[i][1] + arr[i][3] * t);
	}
	sort(p.begin(), p.end());
	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 < n; 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]);
	}

	int idx = 0;
	ll ret = 0;
	for(int i = 0; i < ch.size(); i++) {
		for(int j = 0; j < ch.size(); j++) {
			ret = max(ret, dis(ch[i], ch[j]));
		}
	}
	return ret;
}

int search(int s, int e) {
	if(s + 10 >= e) 	{
		ll dis = 7000000000000000000LL;
		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 << '\n' << cal_dis(ans);
}

Compilation message

dist.cpp: In function 'll cal_dis(int)':
dist.cpp:44:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < ch.size(); i++) {
                 ~~^~~~~~~~~~~
dist.cpp:45:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = 0; j < ch.size(); j++) {
                  ~~^~~~~~~~~~~
dist.cpp:42:6: warning: unused variable 'idx' [-Wunused-variable]
  int idx = 0;
      ^~~
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 380 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 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 380 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 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 17 ms 424 KB Output is correct
12 Correct 37 ms 460 KB Output is correct
13 Correct 14 ms 492 KB Output is correct
14 Correct 17 ms 488 KB Output is correct
15 Incorrect 10 ms 376 KB Output isn't correct
16 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 212 ms 2360 KB Output is correct
2 Correct 156 ms 2304 KB Output is correct
3 Correct 163 ms 2348 KB Output is correct
4 Execution timed out 2045 ms 2720 KB Time limit exceeded
5 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 380 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 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 17 ms 424 KB Output is correct
12 Correct 37 ms 460 KB Output is correct
13 Correct 14 ms 492 KB Output is correct
14 Correct 17 ms 488 KB Output is correct
15 Incorrect 10 ms 376 KB Output isn't correct
16 Halted 0 ms 0 KB -