Submission #407355

#	Time	Username	Problem	Language	Result	Execution time	Memory
407355		arayi	Chessboard (IZhO18_chessboard)	C++17	100 / 100	525 ms	5840 KiB

chessboard

//Arayi
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <math.h>
#include <vector>
#include <cstring>
#include <ctime>
#include <set>
#include <bitset>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <ctime>
#include <climits>
#include <cassert>
#include <chrono>
#include <random>
#include <complex>

#define fr first
#define sc second
#define MP make_pair
#define ad push_back
#define PB push_back
#define fastio ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define lli long long int
#define y1 arayikhalatyan
#define j1 jigglypuff
#define ld long double
#define itn int
#define pir pair<int, int>
#define all(x) (x).begin(), (x).end()
#define str string
#define enl endl
#define en endl
#define cd complex<long double>
#define vcd vector<cd>
#define vii vector<int>
#define vlli vector<lli>
using namespace std;

lli gcd(lli a, lli b) { return (b == 0LL ? a : gcd(b, a % b)); }
ld dist(ld x, ld y1, ld x2, ld y2)
{
    return sqrt((x - x2) * (x - x2) + (y1 - y2) * (y1 - y2));
}
lli S(lli a)
{
    return (a * (a + 1LL)) / 2;
}
mt19937 rnd(363542);
char vow[] = { 'a', 'e', 'i', 'o', 'u' };
int dx[] = { 0, -1, 0, 1, -1, -1, 1, 1, 0 };
int dy[] = { -1, 0, 1, 0, -1, 1, -1, 1, 0 };


const int N = 5e6 + 30;
const lli mod = 1e9 + 7;
const ld pi = acos(-1);
const ld e = log2(3);
const int T = 1000;

lli bp(lli a, lli b = mod - 2LL)
{
    lli ret = 1;
    while (b)
    {
        if (b & 1) ret *= a, ret %= mod;
        a *= a;
        a %= mod;
        b >>= 1;
    }
    return ret;
}
ostream& operator<<(ostream& c, pir a)
{
    c << a.fr << " " << a.sc;
    return c;
}
template<class T>
void maxi(T& a, T b)
{
    a = max(a, b);
}
template <class T>
void mini(T& a, T b)
{
    a = min(a, b);
}


lli n, k;
lli x1[N], x2[N], y1[N], y2[N];
lli sum, pat = mod * mod;
lli sp(lli i, lli j, lli x)
{
    if (((i / x) + (j / x)) % 2 == 0) return 1;
    return 0;
}
lli f1(lli x1, lli y1, lli x2, lli y2, lli x)
{
    return (x2 - x1 + 1LL) * 1LL * (y2 - y1 + 1LL) * sp(x1, y1, x);
}
lli f2(lli x1, lli y1, lli x2, lli y2, lli x)
{
    lli l = (y1 - 1 + x) / x, r = y2 / x;
    l *= x, r *= x;
    if (r < l) return f1(x1, y1, x2, y2, x);
    lli sm = f1(x1, y1, x2, l - 1, x) + f1(x1, r, x2, y2, x);
    lli s = (r - l) / x; s = (s + sp(x1, l, x)) / 2;
    sm += s * x * 1LL * (x2 - x1 + 1LL);
    return sm;
}
int main()
{
    fastio;
    cin >> n >> k;
    for (int i = 0; i < k; i++)
    {
        cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
        x1[i]--, x2[i]--, y1[i]--, y2[i]--;
        sum += (x2[i] - x1[i] + 1) * 1LL * (y2[i] - y1[i] + 1);
    }
    for (lli x = 1; x < n; x++)
    {
        if (n % x) continue;
        lli sm = 0;
        lli ssp = ((n / x) * (n / x) + 1LL) / 2LL;
        ssp *= x * x;
        //cout << x << " " << ssp << endl;
        for (int i = 0; i < k; i++)
        {
            bool bl1 = ((x1[i] / x) != (x2[i] / x));
            bool bl2 = ((y1[i] / x) != (y2[i] / x));
            if (!bl1 && !bl2) sm += f1(x1[i], y1[i], x2[i], y2[i], x);
            else if (bl1 && !bl2) sm += f2(y1[i], x1[i], y2[i], x2[i], x);
            else if (!bl1 && bl2) sm += f2(x1[i], y1[i], x2[i], y2[i], x);
            else
            {
                lli i2 = (x2[i] / x) * x, j2 = (y2[i] / x) * x;
                lli i1 = ((x1[i] - 1 + x) / x) * x, j1 = ((y1[i] - 1 + x) / x) * x;
                //cout << i1 << " " << i2 << " " << j1 << " " << j2 << endl;
                sm += f2(y1[i], i1, j1 - 1, x2[i], x) + f2(i2, j1, x2[i], y2[i], x) + f2(j2, x1[i], y2[i], i2 - 1, x) + f2(x1[i], y1[i], i1 - 1, j2 - 1, x);
                lli s = ((i2 - i1) / x) * 1LL * ((j2 - j1) / x);
                sm += x * x * ((s + sp(i1, j1, x)) / 2LL);
            }
        }
        //cout << sm << endl;
        lli s = n * n - ssp - sum + sm;
        //cout << s << endl;
        mini(pat, s + sm);
        mini(pat, n * n - s - sm);
    }
    cout << pat << endl;
    return 0;
}


/*

    __
  *(><)*
    \/ /
    ||/
  --||
    ||
    /\
   /  \
  /    \

*/

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