Submission #90321

#	Time	Username	Problem	Language	Result	Execution time	Memory
90321		HardNut	Chessboard (IZhO18_chessboard)	C++17	70 / 100	1080 ms	3808 KiB

chessboard

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;
const long long INF = 1e18 + 5;
const int MAXN = 1e6;
const int base = 317;

typedef long long ll;

const ll bs = 1e5 + 1;
const ll mod = 998244353;

#define int ll

ll ans = INF, n, k, xx[N], yy[N], xx1[N], yy1[N];

int fndl(int cor, int x) {
    if (cor % x == 0)
        return cor;
    return (cor / x + 1) * x;
}

int fndr(int cor, int x) {
    if (cor % x == x - 1)
        return cor;
    return (cor / x) * x - 1;
}

void clc(int x, int y, int xx, int yy, ll &res1, ll &res2, int len) {
    if (yy < y || xx < x)
        return;
    int rs1 = 0, rs2 = 0;
    int n1 = xx - x + 1, n2 = yy - y + 1;
    rs1 = (n1 / len) * (n2 / len) / 2 * len * len;
    rs2 = n1 * n2 - rs1;
    swap(rs1, rs2);
    if ((x / len) % 2 != (y / len) % 2) {
        swap(rs1, rs2);
    }
    res1 += rs1;
    res2 += rs2;
}

void clcx(int x, int y, int xx, int yy, ll &res1, ll &res2, int len) {
    if (yy < y || xx < x)
        return;
    int nn = xx - x + 1;
    int ne = yy - y + 1;
    ll rs1 = (nn / len) / 2 * len * ne,
    rs2 = nn * ne - rs1;
    swap(rs1, rs2);
    if ((x / len) % 2 != (y / len) % 2)
        swap(rs1, rs2);
    res1 += rs1;
    res2 += rs2;
}

void clcy(int x, int y, int xx, int yy, ll &res1, ll &res2, int len) {
    if (yy < y || xx < x)
        return;
    int nn = yy - y + 1;
    int ne = xx - x + 1;
    ll rs1 = (nn / len) / 2 * len * ne,
    rs2 = nn * ne - rs1;
    swap(rs1, rs2);
    if ((x / len) % 2 != (y / len) % 2)
        swap(rs1, rs2);
    res1 += rs1;
    res2 += rs2;
}

void clc_cor(int x, int y, int xx, int yy, ll &res1, ll &res2, int len) {
    if (yy < y || xx < x)
        return;
    if ((x / len) % 2 == (y / len) % 2) {
        res1 += (xx - x + 1) * (yy - y + 1);
    } else {
        res2 += (xx - x + 1) * (yy - y + 1);
    }
}

ll calc(ll x) {
    ll res1 = 0, res2 = 0;
    for (int i = 1; i <= k; i++) {
        int x1 = fndl(xx[i], x),
        y1 = fndl(yy[i], x),
        x2 = fndr(xx1[i], x),
        y2 = fndr(yy1[i], x);
        if (x1 > x2 && y1 > y2) {
            clc_cor(xx[i], yy[i], xx1[i], yy1[i], res1, res2, x);
            continue;
        }
        clc(x1, y1, x2, y2, res1, res2, x);
        clcx(x1, yy[i], x2, y1 - 1, res1, res2, x);
        clcx(x1, y2 + 1, x2, yy1[i], res1, res2, x);
        clcy(xx[i], y1, x1 - 1, y2, res1, res2, x);
        clcy(x2 + 1, y1, xx1[i], y2, res1, res2, x);
        if (x1 > xx[i] && y1 > yy[i])
            clc_cor(xx[i], yy[i], x1 - 1, y1 - 1, res1, res2, x);
        if (x2 < xx1[i] && y1 > yy[i])
            clc_cor(x2 + 1, yy[i], xx1[i], y1 - 1, res1, res2, x);
        if (xx[i] < x1 && yy1[i] > y2)
            clc_cor(xx[i], y2 + 1, x1 - 1, yy1[i], res1, res2, x);
        if (x2 < xx1[i] && yy1[i] > y2)
            clc_cor(x2 + 1, y2 + 1, xx1[i], yy1[i], res1, res2, x);
    }
    ll c1 = (n / x) * (n / x) / 2 * x * x;
    ll c2 = n * n - c1;
    return min(c1 - res2 + res1, c2 - res1 + res2);
}

main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> k;
    for (int i = 1; i <= k; i++) {
        cin >> xx[i] >> yy[i] >> xx1[i] >> yy1[i];
        xx[i]--;
        yy[i]--;
        xx1[i]--;
        yy1[i]--;
    }
    for (int i = 1; i <= sqrt(n); i++) {
        if (n % i == 0) {
            ans = min(ans, calc(i));
            if (i != 1)
                ans = min(ans, calc(n / i));
        }
    }
    cout << ans;
    return 0;
}
/*

*/

Compilation message (stderr)

chessboard.cpp:114:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^

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