Submission #572134

#	Time	Username	Problem	Language	Result	Execution time	Memory
572134		piOOE	Triangles (CEOI18_tri)	C++17	0 / 100	1 ms	324 KiB

tri

#include <bits/stdc++.h>
#include "trilib.h"

using namespace std;

#define sz(x) ((int)size(x))
#define all(x) begin(x), end(x)
#define trace(x) cout << #x << ": " << (x) << endl;

typedef long long ll;

mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l, int r) { return (int) ((ll) rnd() % (r - l + 1)) + l; }

const int N = 40000;
const ll infL = 3e18;

int n;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    n = get_n();
    vector<int> ord(n);
    iota(all(ord), 0);
    stable_sort(1 + all(ord), [](int i, int j) {
        return !is_clockwise(1, i + 1, j + 1);
    });
    int x = 0;
    for (int iter = 0; iter < 15; ++iter) {
        vector<int> st;
        for (int i = 0; i < sz(ord); ++i) {
            if (ord[i] == x) {
                if (i) {
                    rotate(begin(ord), begin(ord) + i, end(ord));
                    break;
                }
            }
        }
        for (int i: ord) {
            while (sz(st) > 1 && is_clockwise(st.end()[-2] + 1, st.back() + 1, i + 1)) {
                st.pop_back();
            }
            st.push_back(i);
        }
        ord = st;
        x = ord[rand(0, sz(ord) - 1)];
    }
    cout << sz(ord);
    return 0;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 25