Submission #378679

#	Time	Username	Problem	Language	Result	Execution time	Memory
378679		abc864197532	Chessboard (IZhO18_chessboard)	C++17	8 / 100	58 ms	3256 KiB

chessboard

#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define pii pair<int, int>
#define pll pair<lli, lli>
#define X first
#define Y second
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define test(x) cout << #x << ' ' << x << endl
#define printv(x) {\
    for (auto a : x) cout << x << ' ';\
    cout << endl;\
}
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
const int N = 2000000;

int main () {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, k;
    cin >> n >> k;
    vector <int> p;
    for (int i = 1; i < n; ++i) if (n % i == 0) p.pb(i);
    if (k == 0) {
        lli ans = 1ll * n * n;
        for (int i : p) {
            ans = min(ans, 1ll * i * i * (1ll * (n / i) * (n / i) / 2));
        }
        cout << ans << endl;
        return 0;
    }
    set <pii> s;
    for (int i = 0, x1, y1, x2, y2; i < n; ++i) {
        cin >> x1 >> y1 >> x2 >> y2, --x1, --y1;
        s.insert({x1, y1});
    }
    lli ans = 1ll * n * n;
    for (int i : p) {
        lli cur = 1ll * i * i * (1ll * (n / i) * (n / i) / 2);
        for (pii a : s) {
            int x, y;
            tie(x, y) = a;
            x /= i, y /= i;
            if ((x ^ y) & 1) {
                cur--;
            } else {
                cur++;
            }
        }
        ans = min({ans, cur, 1ll * n * n - cur});
    }
    cout << ans << endl;
}

/*
6 8
3 3 3 3
1 2 1 2
3 4 3 4
5 5 5 5
4 3 4 3
4 4 4 4
2 1 2 1
3 6 3 6
 */

• Subtask 1: 8 / 8
• Subtask 2: 0 / 8
• Subtask 3: 0 / 15
• Subtask 4: 0 / 16
• Subtask 5: 0 / 23
• Subtask 6: 0 / 30