Submission #495178

# Submission time Handle Problem Language Result Execution time Memory
495178 2021-12-18T06:08:27 Z armashka Chessboard (IZhO18_chessboard) C++17
39 / 100
69 ms 4932 KB
#include <bits/stdc++.h>
 
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#define fast ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
#define all(v) v.begin(),v.end()
#define pb push_back
#define sz size()
#define ft first
#define sd second
 
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef unsigned long long ull;
 
const int N = 1e6 + 5;
const ll M = 1e8;
const ll inf = 1e9;
const ll mod = 1e9;
const double Pi = acos(-1); 
 
ll binpow(ll x, ll ti) { ll res = 1;while (ti){if(ti & 1)res *= x;x *= x;ti >>= 1; x %= mod; res %= mod;} return res;}
ll binmul(ll x, ll ti) { ll res = 0;while (ti){if(ti & 1)res += x;x += x;ti >>= 1; x %= mod; res %= mod;} return res;}
ll nok(ll a, ll b) { return (a*b)/__gcd(abs(a),abs(b)) * (a*b > 0 ? 1 : -1); }
bool odd(ll n) { return (n % 2 == 1); }
bool even(ll n) { return (n % 2 == 0); }            
                     
struct node {
	ll x1, y1, x2, y2;
};
                                               
ll n, k, ans = inf;
bool bl[1005][1005];
node que[100005]; 
 
void check(int razmer) {
	ll cnt = 0;
	for (int i = 1; i <= n; ++ i) {
		for (int j = 1; j <= n; ++ j) {
			int num = ((i + razmer - 1) / razmer) + ((j + razmer - 1) / razmer);
			if (even(num) && !bl[i][j]) ++ cnt;
			if (odd(num) && bl[i][j]) ++ cnt; 
		}
	}
	//cout << razmer << " " << min(cnt, n * n - cnt) << "\n";
	ans = min(ans, min(cnt, n * n - cnt));
	return;
}
 
const void solve(/*Armashka*/) {
	cin >> n >> k;
	ll c1 = (n * n) / 2, c2 = (n * n) - c1, cnt1 = 0, cnt2 = 0;
	bool ok = 1;
	for (int i = 1; i <= k; ++ i) {
		ll x1, y1, x2, y2;
		cin >> x1 >> y1 >> x2 >> y2;
		que[i] = {x1, y1, x2, y2};
		if (x1 % 2 == y1 % 2) ++ cnt2;
		else ++ cnt1;
		if (x1 != x2 || y1 != y2) ok = 0;
	}
	if (ok) {
		vector <ll> v;
		for (int i = 1; i * i <= n; ++ i) {
			if (n % i == 0) {
				v.pb(i);
				if (n / i != i && i > 1) v.pb(n / i);
			}
		}
		for (int j = 0; j < v.sz; ++ j) {
			ll cnt1 = 0, cnt2 = 0;
			for (int i = 1; i <= k; ++ i) {                                                       
				ll num = (que[i].x1 + v[j] - 1) / v[j] + (que[i].y1 + v[j] - 1) / v[j];
				if (odd(num)) ++ cnt1;
				else ++ cnt2;
			}
			//cout << v[j] << " " << (n * n / (v[j] * v[j])) << " " << cnt1 << " " << cnt2 << "\n";
			ll res = (n * n / (v[j] * v[j]) / 2 * v[j] * v[j]) - cnt1 + cnt2;
			ans = min(ans, min(res, n * n - res));
		}
		cout << ans << "\n";
		return;
	}
	for (int i = 1; i <= k; ++ i) {
		for (int j = que[i].x1; j <= que[i].x2; ++ j) {
			for (int h = que[i].y1; h <= que[i].y2; ++ h) bl[j][h] = 1;
		}
	}
	for (int i = 1; i * i <= n; ++ i) {
		if (n % i == 0) {
			check(i);
			if (n / i != i && i > 1) check(n / i);
		}
	}
	cout << ans << "\n";
}
 
signed main() {
    fast;
	//freopen("divide.in", "r", stdin);
	//freopen("divide.out", "w", stdout);
    int tt = 1;
    //cin >> tt;
    while (tt --) {
    	solve();
	}
}
 
/*
 
6 8
3 3 3 3
1 2 1 2
3 4 3 4
5 5 5 5
4 3 4 3
4 4 4 4
2 1 2 1
3 6 3 6
 
*/
 
/*
9 12
1 9 4
1 2 5
2 3 7
2 4 3
4 3 6
3 6 4
8 7 10
6 7 5
5 8 1
9 5 7
5 4 12
6 8 2
2
4 7
5
1 6
5 3
4 8
5 8
1 5
 
*/

Compilation message

chessboard.cpp: In function 'const void solve()':
chessboard.cpp:73:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |   for (int j = 0; j < v.sz; ++ j) {
      |                     ^
chessboard.cpp:55:23: warning: unused variable 'c2' [-Wunused-variable]
   55 |  ll c1 = (n * n) / 2, c2 = (n * n) - c1, cnt1 = 0, cnt2 = 0;
      |                       ^~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 324 KB Output is correct
3 Correct 1 ms 316 KB Output is correct
4 Correct 1 ms 320 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 21 ms 3652 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 320 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 328 KB Output is correct
10 Correct 1 ms 316 KB Output is correct
11 Correct 1 ms 320 KB Output is correct
12 Correct 1 ms 332 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 320 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 328 KB Output is correct
10 Correct 1 ms 316 KB Output is correct
11 Correct 1 ms 320 KB Output is correct
12 Correct 1 ms 332 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 9 ms 1524 KB Output is correct
17 Correct 24 ms 4260 KB Output is correct
18 Correct 31 ms 4888 KB Output is correct
19 Correct 62 ms 4444 KB Output is correct
20 Correct 69 ms 4932 KB Output is correct
21 Correct 23 ms 4084 KB Output is correct
22 Correct 1 ms 332 KB Output is correct
23 Correct 17 ms 2292 KB Output is correct
24 Correct 29 ms 4556 KB Output is correct
25 Correct 4 ms 716 KB Output is correct
26 Correct 18 ms 2920 KB Output is correct
27 Correct 25 ms 3532 KB Output is correct
28 Correct 32 ms 4772 KB Output is correct
29 Correct 10 ms 1832 KB Output is correct
30 Correct 2 ms 336 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 21 ms 3652 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 324 KB Output is correct
3 Correct 1 ms 316 KB Output is correct
4 Correct 1 ms 320 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Incorrect 21 ms 3652 KB Output isn't correct
10 Halted 0 ms 0 KB -