Submission #50842

#	Time	Username	Problem	Language	Result	Execution time	Memory
50842		Nicksechko	Chessboard (IZhO18_chessboard)	C++14	100 / 100	715 ms	2300 KiB

chessboard

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

const int MX = 100 * 1000 + 7;

#define y1 ak_a_kak_podnyat

int x1[MX], y1[MX], x2[MX], y2[MX];

pair<int, int> slv(int l, int r, int s) {
    if (l / s == r / s) {
        int b = l / s;
        if (b & 1) {
            return {0, r - l + 1};
        } else {
            return {r - l + 1, 0};
        }
    } else {
        pair<int, int> a(0, 0);
        int nl = l - l % s + s, nr = r - r % s - 1;
        if ((l / s) % 2 == 0) {
            a.first += nl - l;
        } else {
            a.second += nl - l;
        }
        if ((r / s) % 2 == 0) {
            a.first += r - nr;
        } else {
            a.second += r - nr;
        }
        int bl = (nr - nl + 1) / s;
        if (bl & 1) {
            if ((nl / s) % 2 == 0) {
                a.first += s;
            } else {
                a.second += s;
            }
            bl--;
        }
        a.first += (bl / 2) * s;
        a.second += (bl / 2) * s;
        return a;
    }
}

ll solve(int n, int m, int s) {
    ll g0 = 0, g1 = 0;
    for (int i = 0; i < m; i++) {
        auto p1 = slv(x1[i], x2[i], s);
        auto p2 = slv(y1[i], y2[i], s);
        g0 += 1LL * p1.first * p2.first;
        g0 += 1LL * p1.second * p2.second;
        g1 += 1LL * p1.second * p2.first;
        g1 += 1LL * p1.first * p2.second;
    }
    n /= s;
    ll b0 = (1LL * n * n + 1) / 2 * s * s;
    ll b1 = (1LL * n * n) / 2 * s * s;
    return min(g0 + b1 - g1, g1 + b0 - g0);
}

int main() {
#ifdef AZINO777
    freopen("in", "r", stdin);
#endif
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int n, m;
    scanf("%d %d", &n, &m);
    for (int i = 0; i < m; i++) {
        scanf("%d %d %d %d", &x1[i], &y1[i], &x2[i], &y2[i]);
        x1[i]--;
        y1[i]--;
        x2[i]--;
        y2[i]--;
    }
    ll ans = 2e18;
    for (int i = 1; i < n; i++) {
        if (n % i == 0) {
            ans = min(ans, solve(n, m, i));
        }
    }
    printf("%lld\n", ans);
}

Compilation message (stderr)

chessboard.cpp: In function 'int main()':
chessboard.cpp:72:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~
chessboard.cpp:74:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d %d", &x1[i], &y1[i], &x2[i], &y2[i]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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