#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define ld long double
#define P complex<ld>
const int MOD = 998244353;
bool les(ld a, ld b){
if(a < b && abs(a - b) > 1e-10) return true;
else return false;
}
void solve(){
int n; ld h; cin >> n >> h;
vector<P> mnt(n);
for(int i = 0; i < n; i++){
ld x, y; cin >> x >> y;
mnt[i] = {x, y};
}
vector<pair<ld, ld>> a(n, {-1e18, -1e18});
vector<P> ch;
for(int i = 1; i < n - 1; i++){
bool good = 0;
while(!good){
if((int)ch.size() < 2){
ch.push_back(mnt[i]);
good = 1;
}else{
P p = ch[(int)ch.size() - 1] - ch[(int)ch.size() - 2];
P p1 = mnt[i] - ch[(int)ch.size() - 1];
if(p.real() * p1.imag() - p1.real() * p.imag() >= 0) ch.pop_back();
else{
good = 1;
ch.push_back(mnt[i]);
}
}
}
if(i % 2 == 0){
P p = ch[(int)ch.size() - 2];
ld difhor = mnt[i].real() - p.real();
ld difver = p.imag() - mnt[i].imag();
ld hdif = h - mnt[i].imag();
a[i].first = mnt[i].real() - ((difhor / difver) * hdif);
}
}
ch.resize(0);
for(int i = n - 2; i >= 1; i--){
bool good = 0;
while(!good){
if((int)ch.size() < 2){
ch.push_back(mnt[i]);
good = 1;
}else{
P p = ch[(int)ch.size() - 1] - ch[(int)ch.size() - 2];
P p1 = mnt[i] - ch[(int)ch.size() - 1];
if(p.real() * p1.imag() - p1.real() * p.imag() <= 0) ch.pop_back();
else{
good = 1;
ch.push_back(mnt[i]);
}
}
}
if(i % 2 == 0){
P p = ch[(int)ch.size() - 2];
ld difhor = p.real() - mnt[i].real();
ld difver = p.imag() - mnt[i].imag();
ld hdif = h - mnt[i].imag();
a[i].second = mnt[i].real() + ((difhor / difver) * hdif);
}
}
vector<pair<ld, ld>> v;
for(auto p : a){
if(p.first != -1e18) v.push_back(p);
}
n = v.size();
sort(v.begin(), v.end());
int curr = 0;
ld right = -1e18;
for(int i = 0; i < n; i++){
if(les(right, v[i].first)){
curr++;
right = v[i].second;
}else right = min(right, v[i].second);
}
cout << curr << endl;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
//freopen("inpt.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
//int tt; cin >> tt;
int tt = 1;
for(int t = 1; t <= tt; t++){
solve();
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
1368 KB |
Output is correct |
2 |
Correct |
7 ms |
1368 KB |
Output is correct |
3 |
Correct |
6 ms |
1492 KB |
Output is correct |
4 |
Correct |
51 ms |
9800 KB |
Output is correct |
5 |
Correct |
56 ms |
9968 KB |
Output is correct |
6 |
Correct |
60 ms |
10044 KB |
Output is correct |
7 |
Correct |
511 ms |
89468 KB |
Output is correct |
8 |
Correct |
559 ms |
91580 KB |
Output is correct |
9 |
Correct |
585 ms |
93260 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
468 KB |
Output is correct |
2 |
Correct |
2 ms |
464 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
2 ms |
460 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
2 ms |
468 KB |
Output is correct |
7 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
1368 KB |
Output is correct |
2 |
Correct |
7 ms |
1368 KB |
Output is correct |
3 |
Correct |
6 ms |
1492 KB |
Output is correct |
4 |
Correct |
51 ms |
9800 KB |
Output is correct |
5 |
Correct |
56 ms |
9968 KB |
Output is correct |
6 |
Correct |
60 ms |
10044 KB |
Output is correct |
7 |
Correct |
511 ms |
89468 KB |
Output is correct |
8 |
Correct |
559 ms |
91580 KB |
Output is correct |
9 |
Correct |
585 ms |
93260 KB |
Output is correct |
10 |
Correct |
2 ms |
468 KB |
Output is correct |
11 |
Correct |
2 ms |
464 KB |
Output is correct |
12 |
Correct |
0 ms |
340 KB |
Output is correct |
13 |
Correct |
2 ms |
460 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
2 ms |
468 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
540 ms |
90480 KB |
Output is correct |
18 |
Correct |
555 ms |
90408 KB |
Output is correct |
19 |
Correct |
57 ms |
9852 KB |
Output is correct |
20 |
Correct |
542 ms |
89596 KB |
Output is correct |
21 |
Correct |
60 ms |
9776 KB |
Output is correct |
22 |
Correct |
586 ms |
93436 KB |
Output is correct |
23 |
Correct |
0 ms |
340 KB |
Output is correct |
24 |
Correct |
574 ms |
92672 KB |
Output is correct |
25 |
Correct |
56 ms |
9804 KB |
Output is correct |
26 |
Correct |
633 ms |
93676 KB |
Output is correct |
27 |
Correct |
26 ms |
5108 KB |
Output is correct |