Submission #382770

#	Time	Username	Problem	Language	Result	Execution time	Memory
382770		ne4eHbKa	Planine (COCI21_planine)	C++17	20 / 110	485 ms	57916 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#ifndef _LOCAL
//#pragma GCC optimize("O3,Ofast")
#else
#pragma GCC optimize("O0")
#endif
template<typename t> inline void umin(t &a, const t b) {a = min(a, b);}
template<typename t> inline void umax(t &a, const t b) {a = max(a, b);}
typedef pair<int, int> pii;
typedef long long ll;
typedef long double ld;
typedef int8_t byte;
ll time() {return chrono::system_clock().now().time_since_epoch().count();}
mt19937 rnd(time());
#define ft first
#define sd second
#define len(f) int((f).size())
#define bnd(f) (f).begin(), (f).end()
#define _ <<' '<<
const int inf = 1e9 + 5;
const ll inf64 = 4e18 + 5;
const int md = 998244353;
namespace MD {
    void add(int &a, const int b) {if((a += b) >= md) a -= md;}
    void sub(int &a, const int b) {if((a -= b) < 0) a += md;}
    int prod(const int a, const int b) {return ll(a) * b % md;}
};

const int N = 1e6 + 5;
int h, x[N], y[N], n, m;
vector<pair<ld, ld>> c;
ld f[N];
pii p[N];
bool mk[N];

ld point(int i, int j) { return f[m++] = x[j] + (x[j] - x[i]) * ll(h - y[j]) / ld(y[j] - y[i]); }

void solve() {
    cin >> n >> h;
    for(int i = 0; i < n; ++i)
        cin >> x[i] >> y[i];
    c.clear();
    m = 0;
    for(int i = 2; i + 1 < n; i += 2)
        c.push_back({point(i - 1, i), point(i + 1, i)});
    sort(f, f + m);
    m = unique(f, f + m) - f;
    n = 0;
    for(auto &i : c) {
        p[n++] = {
            lower_bound(f, f + m, i.ft) - f,
            lower_bound(f, f + m, i.sd) - f
        };
    }
    sort(p, p + n);
    memset(mk, 0, n);
    for(int i = 1; i < n; ++i)
        if(p[i].ft == p[i - 1].ft &&
           p[i].sd >= p[i - 1].sd) mk[i] = true;
    for(int i = n - 1, f = +inf; ~i; --i) {
        if(p[i].sd >= f) mk[i] = true;
        umin(f, p[i].sd);
    }
    int ans {};
    for(int i = 0, f = -inf; i < n; ++i) {
        if(mk[i]) continue;
        if(f < p[i].ft) {
            f = p[i].sd;
            ++ans;
        }
    }
    cout << ans << endl;
}

signed main() {
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#ifndef _LOCAL
//    freopen("file.in", "r", stdin);
//    freopen("file.out", "w", stdout);
#else
    system("color a");
    freopen("in.txt", "r", stdin);
    int t; cin >> t;
    while(t--)
#endif
    solve();
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 30
• Subtask 3: 0 / 60