oj.uz

답안 #400925

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
400925 2021-05-08T20:44:30 Z jenkinsser Planine (COCI21_planine) C++17
110 / 110
 302 ms 70456 KB 
#include <bits/stdc++.h>
#define FOR(ii,aa,bb) for(int ii=aa;ii<bb;ii++)
#define for0(ii,bb) FOR(ii,0,bb)
#define for1(ii,bb) FOR(ii,1,bb+1)
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define st first
#define nd second
#define pii pair<int,int>
#define piii pair<int,pii>
#define piiii pair<pii,pii>
#define pdi pair<double,int>
#define vi vector<int>
#define sp " "
#define nl "\n"
#define all(x) x.begin(),x.end()
#define fastio() ios_base::sync_with_stdio(0);cin.tie(0);
#define ll long long
#define int ll

using namespace std;

const int N = 1e5+5;
const int INF = 1e9+5;
const int mod = 998244353;

int n,h;
vector<pii> p;

bool ccw(pii x,pii y,pii z){
    return x.st*(y.nd-z.nd)+y.st*(z.nd-x.nd)+z.st*(x.nd-y.nd)>0;
}

bool cw(pii x,pii y,pii z){
    return x.st*(y.nd-z.nd)+y.st*(z.nd-x.nd)+z.st*(x.nd-y.nd)<0;
}

bool smaller(pii x,pii y){
    return x.st*y.nd<x.nd*y.st;
}

vector<pii> compute1(){
    vector<pii> hull;
    vector<pii> v;
    for(int i=2;i<n;i++){
        while(hull.size()>=2&&ccw(hull[(int)hull.size()-2],hull[(int)hull.size()-1],p[i]))
            hull.pop_back();
        hull.pb(p[i]);
        if(i&1){
            pii a=hull[(int)hull.size()-1];
            pii b=hull[(int)hull.size()-2];
            // cout << a.st << sp << a.nd << sp << b.st << sp << b.nd << sp;
            pii c={(a.st-b.st)*(h-b.nd)+b.st*(a.nd-b.nd),a.nd-b.nd};
            // cout << c.st << sp << c.nd << nl;
            v.pb(c);
        }
    }
    return v;
}

vector<pii> compute2(){
    vector<pii> hull;
    vector<pii> v;
    for(int i=2;i<n;i++){
        while(hull.size()>=2&&cw(hull[(int)hull.size()-2],hull[(int)hull.size()-1],p[i]))
            hull.pop_back();
        hull.pb(p[i]);
        if(i&1){
            pii a=hull[(int)hull.size()-1];
            pii b=hull[(int)hull.size()-2];
            // cout << a.st << sp << a.nd << sp << b.st << sp << b.nd << sp;
            pii c={(a.st-b.st)*(h-b.nd)+b.st*(a.nd-b.nd),a.nd-b.nd};
            // cout << c.st << sp << c.nd << nl;
            v.pb(c);
        }
    }
    return v;    
}

signed main(){
    fastio()
    cin >> n >> h;
    p.resize(n+2);
    for(int i=1;i<=n;i++)
        cin >> p[i].st >> p[i].nd;
    vector<pii> a=compute1();
    reverse(all(p));
    vector<pii> b=compute2();
    reverse(all(b));
    vector<piiii> v;
    for(int i=0;i<(int)a.size();i++){
        v.pb({a[i],b[i]});
    }
    sort(all(v),[](piiii x,piiii y){
        return smaller(x.nd,y.nd);
    });
    pii last=v[0].nd;
    int ans=1;
    for(int i=1;i<(int)v.size();i++){
        if(smaller(last,v[i].st)){
            ans++;
            last=v[i].nd;
        }
    }
    cout << ans << nl;
}

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 1108 KB Output is correct
2 Correct 4 ms 1236 KB Output is correct
3 Correct 4 ms 1236 KB Output is correct
4 Correct 26 ms 8104 KB Output is correct
5 Correct 27 ms 8368 KB Output is correct
6 Correct 31 ms 8484 KB Output is correct
7 Correct 262 ms 66800 KB Output is correct
8 Correct 282 ms 68588 KB Output is correct
9 Correct 284 ms 70456 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 332 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 2 ms 460 KB Output is correct
7 Correct 1 ms 204 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 1108 KB Output is correct
2 Correct 4 ms 1236 KB Output is correct
3 Correct 4 ms 1236 KB Output is correct
4 Correct 26 ms 8104 KB Output is correct
5 Correct 27 ms 8368 KB Output is correct
6 Correct 31 ms 8484 KB Output is correct
7 Correct 262 ms 66800 KB Output is correct
8 Correct 282 ms 68588 KB Output is correct
9 Correct 284 ms 70456 KB Output is correct
10 Correct 2 ms 332 KB Output is correct
11 Correct 1 ms 460 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 460 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 2 ms 460 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 263 ms 67568 KB Output is correct
18 Correct 261 ms 59004 KB Output is correct
19 Correct 27 ms 6616 KB Output is correct
20 Correct 259 ms 58312 KB Output is correct
21 Correct 29 ms 6724 KB Output is correct
22 Correct 276 ms 62016 KB Output is correct
23 Correct 1 ms 332 KB Output is correct
24 Correct 270 ms 61128 KB Output is correct
25 Correct 26 ms 6748 KB Output is correct
26 Correct 302 ms 62196 KB Output is correct
27 Correct 13 ms 3580 KB Output is correct