Submission #378573

#	Time	Username	Problem	Language	Result	Execution time	Memory
378573		2qbingxuan	Chessboard (IZhO18_chessboard)	C++14	100 / 100	1669 ms	4076 KiB

chessboard

#include <bits/stdc++.h>
#ifdef local
#define safe std::cerr<<__PRETTY_FUNCTION__<<" line "<<__LINE__<<" safe\n"
#define debug(a...) qqbx(#a, a)
template <typename ...T> void qqbx(const char *s, T ...a) {
    int cnt = sizeof...(T);
    ((std::cerr << "\033[1;32m(" << s << ") = (") , ... , (std::cerr << a << (--cnt ? ", " : ")\033[0m\n")));
}
#else
#define safe ((void)0)
#define debug(...) ((void)0)
#endif // local

using namespace std;
using ll = int64_t;
const int maxn = 100025;
const ll INF = 9e18;
bool isBlack(int x, int y) {
    return (x + y) & 1;
}

ll calc2d(int x, int y, int k, bool c) {
    if (x < 0 || y < 0) return 0;
    ++x, ++y;
    ll qx = x / k, rx = x % k;
    ll qy = y / k, ry = y % k;
    ll ans = 0;
    ans += ry * k * (isBlack(0, qy) == c ? (qx + 1) / 2 : qx / 2);
    ans += rx * k * (isBlack(qx, 0) == c ? (qy + 1) / 2 : qy / 2);
    ans += 1LL * k * k * (isBlack(0, 0) == c ? (qx * qy + 1) / 2 : qx * qy / 2);
    // debug((isBlack(0, qy+1) == c ? (qx + 1) / 2 : qx / 2));
    debug(rx , k , (isBlack(qx, 0) == c ? (qy + 1) / 2 : qy / 2));
    // debug((isBlack(0, 0) == c ? (qx * qy + 1) / 2 : qx * qy / 2));
    if (isBlack(qx, qy) == c) ans += rx * ry, debug(rx, ry);
    /*
    int res = 0;
    for (int i = 0; i < x; i++)
        for (int j = 0; j < y; j++)
            if (((i / k) + (j / k)) % 2 == c)
                ++res;
    debug(x, y, k, c, ans, res);
    return res;
    */
    return ans;
}
ll calc(int L, vector<tuple<int,int,int,int>> &v, int k) {
    ll res = INF;
    for (int c: {0, 1}) {
        // cerr << "============\n";
        ll ans = calc2d(L-1, L-1, k, c);
        for (auto [lx, ly, rx, ry]: v) {
            debug(lx, ly, rx, ry);
            ans += 1LL * (rx - lx) * (ry - ly);
            ans -= 2LL * (calc2d(rx, ry, k, c) - calc2d(rx, ly, k, c) - calc2d(lx, ry, k, c) + calc2d(lx, ly, k, c));
        }
        debug(ans, k, c);
        res = min(ans, res);
    }
    return res;
}
signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    int L, n;
    cin >> L >> n;
    vector<tuple<int,int,int,int>> rect(n);
    for (auto &[a, b, c, d]: rect) cin >> a >> b >> c >> d, --a, --b, --a, --b, --c, --d;
    ll ans = INF;
    for (int i = 1; i*i <= L; i++) {
        if (L % i == 0) {
            if (i != L) ans = min(ans, calc(L, rect, i));
            if (L/i != L) ans = min(ans, calc(L, rect, L / i));
        }
        if (i*i > L) break;

    }
    cout << ans << '\n';
}
/*
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
 */

Compilation message (stderr)

chessboard.cpp: In function 'll calc(int, std::vector<std::tuple<int, int, int, int> >&, int)':
chessboard.cpp:51:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   51 |         for (auto [lx, ly, rx, ry]: v) {
      |                   ^
chessboard.cpp: In function 'int main()':
chessboard.cpp:66:16: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   66 |     for (auto &[a, b, c, d]: rect) cin >> a >> b >> c >> d, --a, --b, --a, --b, --c, --d;
      |                ^

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