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답안 #950317

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
950317 2024-03-20T08:07:06 Z Baytoro Planine (COCI21_planine) C++17
110 / 110
 632 ms 69844 KB 
#include <bits/stdc++.h>
using namespace std;
#define ios ios::sync_with_stdio(false); cin.tie(NULL);
#define pb push_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define fr first
#define sc second
#define mp make_pair
#define ll long long
#define int ll
#define double long double
const ll INF=1e18,N=1e6+5;
bool cmp(pair<double,double> a, pair<double,double> b){
	if(a.fr==b.fr) return a.sc>b.sc;
	return a.fr<b.fr;
}
int x[N],y[N];
double slope(int a, int b){
	return (y[b]-y[a])/(x[b]-x[a]+0.0);
}
int cross(pair<int,int> a, pair<int,int> b){
	return a.fr*b.sc-a.sc*b.fr;
}
int cross(int a, int b, int c){
	return cross(mp(x[b]-x[a],y[b]-y[a]),mp(x[c]-x[a],y[c]-y[a]));
}
void solve(){
	int n,h;cin>>n>>h;
	for(int i=0;i<n;i++)
		cin>>x[i]>>y[i];
	vector<double> l(n),r(n);
	vector< pair<double,double> > v;
	deque<int> st;
	st.pb(0);
	for(int i=1;i<n;i++){
		while(st.size()>1 && cross(st[st.size()-2],st.back(),i)>0)
			st.pop_back();
		if(i%2==0){
			if(slope(i,st.back())==0) l[i]=-INF;
			else l[i]=x[st.back()]+(h-y[st.back()])/slope(i,st.back());
		}
		
		st.push_back(i);
	}
	while(!st.empty()) st.pop_back();
	st.pb(n-1);
	for(int i=n-2;i>=0;i--){
		while(st.size()>1 && cross(st[st.size()-2],st.back(),i)<0)
			st.pop_back();
		if(i%2==0){
			if(slope(st.back(),i)==0) r[i]=INF;
			else r[i]=x[i]+(h-y[i])/slope(st.back(),i);
		}
		st.push_back(i);
	}
	for(int i=2;i<n-1;i+=2) v.pb(mp(l[i],r[i]));
	sort(all(v),cmp);
	int ans=0;
	double rx=-INF;
	for(int i=0;i<v.size();i++){
		if(v[i].fr<=rx+1e-9){
			if(v[i].sc<=rx+1e-9)
				rx=v[i].sc;
		}
		else{
			ans++;
			rx=v[i].sc;
		}
	}
	//cout<<fixed<<setprecision(3);
	/*for(auto it: v)
		cout<<it.fr<<' '<<it.sc<<endl;*/
	cout<<ans;
}
main(){
	solve();
}

Compilation message

Main.cpp: In function 'void solve()':
Main.cpp:61:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long double, long double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |  for(int i=0;i<v.size();i++){
      |              ~^~~~~~~~~
Main.cpp: At global scope:
Main.cpp:76:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   76 | main(){
      | ^~~~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 3416 KB Output is correct
2 Correct 6 ms 3164 KB Output is correct
3 Correct 6 ms 3256 KB Output is correct
4 Correct 49 ms 12488 KB Output is correct
5 Correct 53 ms 12248 KB Output is correct
6 Correct 62 ms 12248 KB Output is correct
7 Correct 488 ms 69320 KB Output is correct
8 Correct 527 ms 69844 KB Output is correct
9 Correct 580 ms 69308 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 2 ms 2396 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 2 ms 2396 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 2 ms 2392 KB Output is correct
7 Correct 1 ms 2396 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 3416 KB Output is correct
2 Correct 6 ms 3164 KB Output is correct
3 Correct 6 ms 3256 KB Output is correct
4 Correct 49 ms 12488 KB Output is correct
5 Correct 53 ms 12248 KB Output is correct
6 Correct 62 ms 12248 KB Output is correct
7 Correct 488 ms 69320 KB Output is correct
8 Correct 527 ms 69844 KB Output is correct
9 Correct 580 ms 69308 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 2 ms 2396 KB Output is correct
12 Correct 1 ms 2396 KB Output is correct
13 Correct 2 ms 2396 KB Output is correct
14 Correct 1 ms 2396 KB Output is correct
15 Correct 2 ms 2392 KB Output is correct
16 Correct 1 ms 2396 KB Output is correct
17 Correct 509 ms 68024 KB Output is correct
18 Correct 502 ms 64956 KB Output is correct
19 Correct 52 ms 12056 KB Output is correct
20 Correct 506 ms 64936 KB Output is correct
21 Correct 51 ms 12056 KB Output is correct
22 Correct 549 ms 64356 KB Output is correct
23 Correct 1 ms 2392 KB Output is correct
24 Correct 556 ms 64660 KB Output is correct
25 Correct 55 ms 11984 KB Output is correct
26 Correct 632 ms 63928 KB Output is correct
27 Correct 26 ms 7380 KB Output is correct