Submission #99772

#	Time	Username	Problem	Language	Result	Execution time	Memory
99772		choikiwon	Chessboard (IZhO18_chessboard)	C++17	100 / 100	764 ms	4412 KiB

chessboard

#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int MN = 100010;

int N, K;
struct Rect {
    int r1, c1, r2, c2;
};
Rect rect[MN];

int main() {
    scanf("%d %d", &N, &K);

    for(int i = 0; i < K; i++) {
        scanf("%d %d %d %d", &rect[i].r1, &rect[i].c1, &rect[i].r2, &rect[i].c2);
        rect[i].r1--;
        rect[i].c1--;
        rect[i].r2--;
        rect[i].c2--;
    }

    ll mn = 1e18;
    for(int i = 1; i < N; i++) {
        if(N % i == 0) {
            for(int j = 0; j < 2; j++) {
                int n = N / i;

                ll tmp = j? (1LL * n * n + 1) / 2 : 1LL * n * n / 2;
                tmp *= 1LL * i * i;

                for(int k = 0; k < K; k++) {
                    int rr = min(rect[k].r2 + 1, (rect[k].r1 + i) / i * i);
                    int cc = min(rect[k].c2 + 1, (rect[k].c1 + i) / i * i);
                    int br = (rect[k].r2 - rr + 1) / (2 * i) * i;
                    int bc = (rect[k].c2 - cc + 1) / (2 * i) * i;
                    if((rect[k].r2 - rr + 1) % (2 * i) > i) br += (rect[k].r2 - rr + 1) % (2 * i) - i;
                    if((rect[k].c2 - cc + 1) % (2 * i) > i) bc += (rect[k].c2 - cc + 1) % (2 * i) - i;
                    br += rr - rect[k].r1;
                    bc += cc - rect[k].c1;
                    int wr = rect[k].r2 - rect[k].r1 + 1 - br;
                    int wc = rect[k].c2 - rect[k].c1 + 1 - bc;

                    if(j ^ ((rect[k].r1 / i + rect[k].c1 / i) & 1)) tmp -= 1LL * (br - wr) * (bc - wc);
                    else tmp += 1LL * (br - wr) * (bc - wc);
                }

                mn = min(mn, tmp);
            }
        }
    }
    printf("%lld", mn);
}

Compilation message (stderr)

chessboard.cpp: In function 'int main()':
chessboard.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &N, &K);
     ~~~~~^~~~~~~~~~~~~~~~~
chessboard.cpp:19:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d %d", &rect[i].r1, &rect[i].c1, &rect[i].r2, &rect[i].c2);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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