Submission #1114631

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114631		adiyer	Chessboard (IZhO18_chessboard)	C++17	70 / 100	151 ms	5960 KiB

chessboard

#include <bits/stdc++.h>

#define adiyer(); ios_base::sync_with_stdio(0); cin.tie(0);
#define all(x) (x.begin(), x.end())
#define pb push_back

#define int long long

typedef long long ll;

using namespace std;

const int N = 1e5 + 11;
const int mod = 1e9 + 7;
const ll inf = 1e18 + 11;

mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

ll n, m;
ll ax[N], bx[N], ay[N], by[N];

vector < ll > d;

bool check(ll x, ll y, ll sz){
	ll a = x % (sz * 2);
	ll b = y % (sz * 2);
	a = bool(1 <= a && a <= sz);
	b = bool(1 <= b && b <= sz);
	// cout << x << ' ' << y << ' ' << a << ' ' << b << ' ' << sz << ' ' << ((a + b) & 1) << '\n';
	return ((a + b) & 1);
}

void solve(){
	cin >> n >> m;
	for(int i = 1; i <= m; i++) cin >> ax[i] >> ay[i] >> bx[i] >> by[i];
	for(int i = 1; i < n; i++){
		if(n % i == 0){
			d.pb(i);
		}
	}
	ll mn = inf;
	for(int sz : d){
		ll cur1 = ((n / sz) * (n / sz) / 2) * (sz * sz);
		ll cur2 = ((n / sz) * (n / sz) - ((n / sz) * (n / sz) / 2)) * (sz * sz);
		cur1 -= m, cur2 -= m;
		for(int i = 1; i <= m; i++){
			if(!check(ax[i], ay[i], sz)) cur1 += 2;
			else cur2 += 2;
		}
		// cout << sz << ' ' << cur1 << ' ' << cur2 << '\n';
		mn = min(mn, min(cur1, cur2));
	}
	cout << mn;
}

const bool Cases = 0;

signed main(){
	adiyer();
	int CS = 1;
	if(Cases) cin >> CS;
	while(CS--) solve();
}

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