제출 #338439

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
338439		kutbilim_one	Chessboard (IZhO18_chessboard)	C++14	70 / 100	2088 ms	4204 KiB

chessboard

/** kutbilim.one **/
#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(),x.end()
#define int long long
#define endl '\n'
  /*                        
ifstream in("test.txt"); 
#define cin in              

const signed MAX = 1001;
vector< vector<signed> > a(MAX, vector<signed> (MAX, 0));	
*/
int n, k;

bool isprime(int n){
	if(n == 2) return true;
	for(int i = 2; i*i <= n; i++)
		if(n%i == 0) return false;
	return true;
}

void solve_1(){
	int result = INT_MAX;
	for(int i = 1; i < n; i++){
		if(n%i) continue;
		result = min(result, ((n*n)/(i*i)/2)*(i*i));
	}		
	cout << result;
}

void solve_2(){
	int cnt[2] = {0, 0};
	for(int i = 1; i <= k; i++){
		int x1, y1, x2, y2;
		cin >> x1 >> y1 >> x2 >> y2;
		for(int x = x1; x <= x2; x++)
		for(int y = y1; y <= y2; y++){
			//a[x][y] = 1;
			cnt[(x+y)%2]++;	
		} 				
	}
	
	cout << min(n*n/2-cnt[1] + cnt[0], n*n/2+1-cnt[0] + cnt[1]);
}

void solve_3_4(){
	vector<pair<int, int>> sides(n, {0, 0}); 
	vector<int> f;
	for(int i = 1; i*i <= n; i++){
		if(n % i == 0){
			f.push_back(i);
			if(i != 1) f.push_back(n/i);
		}
	}	

	for(int i = 1; i <= k; i++){
		int x1, y1, x2, y2;
		cin >> x1 >> y1 >> x2 >> y2;
		for(int x = x1; x <= x2; x++)
		for(int y = y1; y <= y2; y++){
			//a[x][y] = 1;	
			for(auto d : f){
				if(((x+d-1)/d+(y+d-1)/d) % 2) sides[d].first++;
				else sides[d].second++; 
			}
		} 				
	}

	int result = LONG_MAX;
	for(auto d : f){
		result = min(
			result,
			((n*n)/(d*d)/2)*(d*d)+(d*d) - sides[d].second + sides[d].first
		);  
		result = min(
			result,
			((n*n)/(d*d)/2)*(d*d) - sides[d].first + sides[d].second
		);
	}
	cout << result;
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    cin >> n >> k;
    
    if(k == 0){
    	solve_1();
    }else if(isprime(n)){
    	solve_2();
    }else{
    	solve_3_4();
    }
    
    return 0;
}

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