제출 #674974

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
674974		LucaIlie	Chessboard (IZhO18_chessboard)	C++17	100 / 100	755 ms	5836 KiB

chessboard

#include <bits/stdc++.h>

#define int long long

using namespace std;

const int maxK = 1e5;

struct rectangle {
    int l1, c1, l2, c2;
};

int l;
rectangle black[maxK];

int nxt( int x ) {
    return (x / l + 1) * l;
}

int prv( int x ) {
    return x / l * l - 1;
}

long long wbSq( int lin, int col, bool color ) {
    if ( lin == 0 || col == 0 )
        return 0;
    return ((lin / 2) * ((col + 1) / 2) + ((lin + 1) / 2) * (col / 2) - ((lin + 1) / 2) * ((col + 1) / 2) - ((lin / 2) * (col / 2))) * (color == 0 ? 1 : -1);
}

long long getCost( rectangle r ) {
    int l1 = r.l1, c1 = r.c1, l2 = r.l2, c2 = r.c2;
    long long cost = 0;

    if ( l1 / l == l2 / l && c1 / l == c2 / l )
        cost += (l2 - l1 + 1) * (c2 - c1 + 1) * wbSq( 1, 1, (l1 / l + c1 / l) % 2 );
    else if ( l1 / l == l2 / l ) {
        cost += (l2 - l1 + 1) * (nxt( c1 ) - c1) * wbSq( 1, 1, (l1 / l + c1 / l) % 2 );
        cost += (l2 - l1 + 1) * (c2 - prv( c2 )) * wbSq( 1, 1, (l2 / l + c2 / l) % 2 );

        cost += l * (l2 - l1 + 1) * wbSq( 1, c2 / l - c1 / l - 1, (l1 / l + nxt( c1 ) / l) % 2 );
    } else if ( c1 / l == c2 / l ) {
        cost += (nxt( l1 ) - l1) * (c2 - c1 + 1) * wbSq( 1, 1, (l1 / l + c2 / l) % 2 );
        cost += (l2 - prv( l2 )) * (c2 - c1 + 1) * wbSq( 1, 1, (l2 / l + c2 / l) % 2 );

        cost += l * (c2 - c1 + 1) * wbSq( l2 / l - l1 / l - 1, 1, (nxt( l1 ) / l + c1 / l) % 2 );
    } else {
        cost += (nxt( l1 ) - l1) * (nxt( c1 ) - c1) * wbSq( 1, 1, (l1 / l + c1 / l) % 2 );
        cost += (nxt( l1 ) - l1) * (c2 - prv( c2 )) * wbSq( 1, 1, (l1 / l + c2 / l) % 2 );
        cost += (l2 - prv( l2 )) * (nxt( c1 ) - c1) * wbSq( 1, 1, (l2 / l + c1 / l) % 2 );
        cost += (l2 - prv( l2 )) * (c2 - prv( c2 )) * wbSq( 1, 1, (l2 / l + c2 / l) % 2 );

        cost += l * (nxt( l1 ) - l1) * wbSq( 1, c2 / l - c1 / l - 1, (l1 / l + nxt( c1 ) / l) % 2 );
        cost += l * (nxt( c1 ) - c1) * wbSq( l2 / l - l1 / l - 1, 1, (nxt( l1 ) / l + c1 / l) % 2 );
        cost += l * (l2 - prv( l2 )) * wbSq( 1, c2 / l - c1 / l - 1, (l2 / l + nxt( c1 ) / l) % 2 );
        cost += l * (c2 - prv( c2 )) * wbSq( l2 / l - l1 / l - 1, 1, (nxt( l1 ) / l + c2 / l) % 2 );

        cost += l * l * wbSq( l2 / l - l1 / l - 1, c2 / l - c1 / l - 1, (nxt( l1 ) / l + nxt( c1 ) / l) % 2 );
    }


    return cost;
}

signed main() {
    int n, k;
    long long cost, minCost;

    cin >> n >> k;
    for ( int i = 0; i < k; i++ ) {
        cin >> black[i].l1 >> black[i].c1 >> black[i].l2 >> black[i].c2;
        black[i].l1--;
        black[i].c1--;
        black[i].l2--;
        black[i].c2--;
    }

    minCost = n * n;
    for ( l = 1; l < n; l++ ) {
        if ( n % l == 0 ) {
            int x = (n / l + 1) / 2, y = n / l / 2;

            cost = (l * l) * (x * x + y * y);
            for ( int i = 0; i < k; i++ )
                cost += getCost( black[i] );
            minCost = min( minCost, cost );

            cost = 2 * x * y * l * l;
            for ( int i = 0; i < k; i++ )
                cost -= getCost( black[i] );
            minCost = min( minCost, cost );
        }
    }

    cout << minCost;

    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