Submission #838204

#	Time	Username	Problem	Language	Result	Execution time	Memory
838204		EntityPlantt	Planine (COCI21_planine)	C++17	20 / 110	205 ms	15916 KiB

Main

#include <cstdio>
#include <algorithm>
using namespace std;
typedef long long ll;
struct frac {
    ll x, y;
    void upd() {
        if (y < 0LL) {
            x *= -1LL;
            y *= -1LL;
        }
    }
    bool operator<(const frac &f) const {
        return x * f.y < y * f.x;
    }
} l;
ll n, h, i, c = 1, x1, y1, x2, y2, x3, y3;
pair <frac, frac> inte[500005];
int main() {
    scanf("%lld%lld%lld%lld%lld%lld", &n, &h, &x3, &y3, &x3, &y3);
    if (n == 3) {
        printf("0");
        return 0;
    }
    n = n / 2 - 1;
    for (i = 0; i < n; i++) {
        x1 = x3; y1 = y3;
        scanf("%lld%lld%lld%lld", &x2, &y2, &x3, &y3);
        /*inte[i].first = {x1 * (y1 - y2) + (h - y1) * (x1 - x2), y1 - y2};
        inte[i].second = {x2 * (y2 - y3) + (h - y2) * (x2 - x3), y2 - y3};*/
        inte[i].first = {x2 * (y1 - y2) + (h - y2) * (x1 - x2), y1 - y2};
        inte[i].second = {x2 * (y3 - y2) + (h - y2) * (x3 - x2), y3 - y2};
        inte[i].first.upd();
        inte[i].second.upd();
    }
    sort(inte, inte + n, [](auto &a, auto &b) { return a.second < b.second; });
    l = inte[0].second;
    for (i = 1; i < n; i++) {
        if (l < inte[i].first) {
            l = inte[i].second;
            c++;
        }
    }
    printf("%lld", c);
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:20:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     scanf("%lld%lld%lld%lld%lld%lld", &n, &h, &x3, &y3, &x3, &y3);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:28:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         scanf("%lld%lld%lld%lld", &x2, &y2, &x3, &y3);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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