Submission #1107912

#	Time	Username	Problem	Language	Result	Execution time	Memory
1107912		Muhammet	Chessboard (IZhO18_chessboard)	C++17	39 / 100	53 ms	9808 KiB

chessboard

#include <bits/stdc++.h>

using namespace std;

int main(){
	ios::sync_with_stdio(false); cin.tie(nullptr);

	int n, k;
	cin >> n >> k;
	vector <int> x1(k+1), y1(k+1), x2(k+1), y2(k+1);
	if(n > 1000){
		int cnt1 = 0, cnt2 = 0, cnt3 = 0, cnt4 = 0;
		for(int i = 1; i <= k; i++){
			cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
			if(x1[i] % 2 == 1){
				if(y1[i] % 2 == 1) cnt1++;
				else cnt2++;
			}
			if(x1[i] % 2 == 0){
				if(y1[i] % 2 == 1) cnt3++;
				else cnt4++;
			}
		}
		int ans = ((((n+1)/2) * ((n+1)/2)) - cnt1) + ((((n)/2) * ((n)/2)) - cnt4) + (k-(cnt4+cnt1));
		ans = min(((((n)/2) * ((n)/2)) - cnt3) + ((((n+1)/2) * ((n+1)/2)) - cnt2) + (k-(cnt2+cnt3)), ans);
		cout << ans;
		return 0;
	}
	vector <vector <int>> a(n+1, vector <int> (n+1,0)), dp(n+1, vector <int> (n+1,0));
	for(int i = 1; i <= k; i++){
		cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
		for(int i1 = x1[i]; i1 <= x2[i]; i1++){
			for(int j1 = y1[i]; j1 <= y2[i]; j1++){
				a[i1][j1] = 1;
			}
		}
	}
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= n; j++){
			dp[i][j] = (dp[i-1][j] + dp[i][j-1] - dp[i-1][j-1] + a[i][j]);
		}
	}
	vector <int> v;
	for(int i = 1; i < n; i++){
		if(n % i == 0){
			v.push_back(i);
		}
	}
	int ans = n*n;
	for(auto x : v){
		int y = 0, y1 = 0;
		bool tr = 1;
		for(int i = 1; i <= n; i += x){
			int cnt = 0;
			for(int j = 1; j <= n; j += x){
				cnt++;
				if(cnt % 2 == tr){
					y1 += (dp[i+x-1][j+x-1] - dp[i-1][j+x-1] - dp[i+x-1][j-1] + dp[i-1][j-1]);
					y += ((x*x) - (dp[i+x-1][j+x-1] - dp[i-1][j+x-1] - dp[i+x-1][j-1] + dp[i-1][j-1]));
				}
				else {
					y += (dp[i+x-1][j+x-1] - dp[i-1][j+x-1] - dp[i+x-1][j-1] + dp[i-1][j-1]);
					y1 += ((x*x) - (dp[i+x-1][j+x-1] - dp[i-1][j+x-1] - dp[i+x-1][j-1] + dp[i-1][j-1]));
				}
			}
			tr = (1-tr);
		}
		ans = min(ans,y);
		ans = min(ans,y1);
	}
	cout << ans;
}

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