oj.uz

Submission #72317

# Submission time Handle Problem Language Result Execution time Memory
72317 2018-08-26T07:02:06 Z 마릴린 희정(#2180, gs14004, ho94949) Hill Reconstruction (FXCUP3_hill) C++17
100 / 100
 537 ms 7196 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long lint;
typedef long double llf;
typedef pair<int, int> pi;
const int MAXN = 300050;

int n; lint c;
pi den, a[MAXN];
vector<pi> stk;

lint ccw(pi a, pi b, pi c){
	int dx1 = b.first - a.first;
	int dy1 = b.second - a.second;
	int dx2 = c.first - a.first;
	int dy2 = c.second - a.second;
	return 1ll * dx1 * dy2 - 1ll * dy1 * dx2;
}

bool big_giulgi(pi a, pi b, llf c){
	return (b.second - a.second) > (b.first - a.first) * c;
}

lint trial(llf x){
	stk.clear();
	stk.push_back(a[0]);
	lint ans = 0;
	for(int i=1; i<n; i++){
		while(stk.size() >= 2 && big_giulgi(stk.back(), a[i], x)){
			ans += ccw(stk[stk.size()-2], stk.back(), a[i]);
			stk.pop_back();
		}
		if(big_giulgi(stk.back(), a[i], x)){
			return 3e18;
		}
		stk.push_back(a[i]);
	}
	return ans;
}

bool cmp(pi a, pi b){
	return 1ll * a.first * b.second < 1ll * b.first * a.second;
}

int gcd(int x, int y){ return y ? gcd(y, x%y) : x; }

int main(){
	scanf("%d %lld",&n,&c);
	c <<= 1;
	for(int i=0; i<n; i++) scanf("%d",&a[i].first);
	for(int i=0; i<n; i++) scanf("%d",&a[i].second);
	long double s = 0, e = 2e9;
	for(int i=0; i<100; i++){
		long double m = (s+e)/2;
		if(trial(m) <= c) e = m;
		else s = m;
	}
	assert(trial(e) <= c);
	pi ans(0, 1);
	for(int i=1; i<stk.size(); i++){
		ans = max(ans, pi(stk[i].second - stk[i-1].second, stk[i].first - stk[i-1].first), cmp); 
	}
	int g = gcd(ans.first, ans.second);
	ans.first /= g;
	ans.second /= g;
	printf("%d/%d\n", ans.first, ans.second);
}

Compilation message

hill.cpp: In function 'int main()':
hill.cpp:60:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1; i<stk.size(); i++){
               ~^~~~~~~~~~~
hill.cpp:48:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %lld",&n,&c);
  ~~~~~^~~~~~~~~~~~~~~~~
hill.cpp:50:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0; i<n; i++) scanf("%d",&a[i].first);
                         ~~~~~^~~~~~~~~~~~~~~~~~
hill.cpp:51:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0; i<n; i++) scanf("%d",&a[i].second);
                         ~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
32.0 / 32.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 3 ms 432 KB Output is correct
4 Correct 3 ms 432 KB Output is correct
5 Correct 5 ms 468 KB Output is correct
6 Correct 3 ms 468 KB Output is correct
7 Correct 3 ms 596 KB Output is correct
8 Correct 4 ms 596 KB Output is correct

Subtask #2
68.0 / 68.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 3 ms 432 KB Output is correct
4 Correct 3 ms 432 KB Output is correct
5 Correct 5 ms 468 KB Output is correct
6 Correct 3 ms 468 KB Output is correct
7 Correct 3 ms 596 KB Output is correct
8 Correct 4 ms 596 KB Output is correct
9 Correct 337 ms 7040 KB Output is correct
10 Correct 307 ms 7040 KB Output is correct
11 Correct 537 ms 7104 KB Output is correct
12 Correct 483 ms 7152 KB Output is correct
13 Correct 214 ms 7152 KB Output is correct
14 Correct 159 ms 7152 KB Output is correct
15 Correct 498 ms 7156 KB Output is correct
16 Correct 326 ms 7196 KB Output is correct
17 Correct 415 ms 7196 KB Output is correct
18 Correct 209 ms 7196 KB Output is correct
19 Correct 229 ms 7196 KB Output is correct