Submission #167829

#	Time	Username	Problem	Language	Result	Execution time	Memory
167829		abil	Chessboard (IZhO18_chessboard)	C++14	70 / 100	1348 ms	5624 KiB

chessboard

#include <bits/stdc++.h>

#define fr first
#define sc second
#define pb push_back
#define mk make_pair
#define all(s) s.begin(),s.end()
#define int long long

using namespace std;

const int N = (1e5 + 12);
const int mod = (1e9 + 7);
const int INF = (0x3f3f3f3f);

int ans = 1e18;
int n, k, x[2][N], y[2][N];

int get(int x1, int y1, int x2, int y2, int div,int f){
	int blx = (x1 + div - 1ll) / div, blx2 = (x2 + div - 1ll) / div;
	int bly = (y1 + div - 1ll) / div, bly2 = (y2 + div - 1ll) / div;
	int res = 0ll, odd, even;
	if(blx == blx2){
		int val = x2 - x1 + 1ll;
		if(bly != bly2){
			int end = bly * div;
			val = val * (end - y1 + 1ll);
			bly++;
			if(bly2 > bly){
				int dif = bly2 - bly + 1ll;
				val += dif / 2ll * (x2 - x1 + 1ll);
			}
			int p = (x2 - x1 + 1ll) * (y2 - y1 + 1ll);
			p = p - val;
			if(((bly - 1ll) + blx) % 2ll == f){
				res += val;
			}
			else{
				res += p;
			}			
		}
		else{
			int p = (x2 - x1 + 1ll) * (y2 - y1 + 1ll);
			if((bly + blx) % 2ll == f){
				res += p;
			}
		}
	}
	else{
		int end = blx * div;
		int odd = end - x1 + 1ll;
		blx++;
		if(blx2 > blx){
			int dif = blx2 - blx + 1ll;
			odd += dif / 2ll * div;
		}
		int op = (x2 - x1 + 1);
		op -= odd;
		if(bly != bly2){
			end = bly * div;
			int val = end - y1 + 1ll;
			val = val * odd;
			bly++;
			if(bly2 >= bly){
				int dif = bly2 - bly + 1ll;
				val += dif / 2ll * odd;
				val += (dif - dif / 2ll) * op;
			}
			int p = (x2 - x1 + 1ll) * (y2 - y1 + 1ll);
			p = p - val;
			if((bly + blx) % 2ll == f){
				res += val;
			}
			else{
				res += p;
			}
		}
		else{
			int p = (y2 - y1 + 1ll) * odd;
			if(((blx - 1ll) + bly) % 2ll == f){
				res += p;
			}
		}
	}
	return res;
}


void calc(int div){
	int bl = n / div, cnt = 0ll, x1, y1, cnt1 = 0ll, x2, y2;
	if(bl & 1ll){
		cnt += div * div * ((bl + 1ll) / 2ll) * ((bl + 1ll) / 2ll);
		cnt += div * div * (bl / 2ll) * (bl / 2);
		cnt1 = n * n - cnt;
		for(int i = 1;i <= k; i++){
			x1 = x[0ll][i];
			y1 = y[0ll][i];
			x2 = x[1ll][i];
			y2 = y[1ll][i];
			cnt -= get(x1, y1, x2, y2, div, 0ll);
			cnt += get(x1, y1, x2, y2, div, 1ll);
			cnt1 += get(x1, y1, x2, y2, div, 0ll);
			cnt1 -= get(x1, y1, x2, y2, div, 1ll);
		}
		ans = min(ans, cnt);
		ans = min(ans, cnt1);
	}
	else{
		cnt += div * div * (bl / 2ll) * bl;
		cnt1 = n * n - cnt;
		for(int i = 1ll;i <= k; i++){
			x1 = x[0ll][i];
			y1 = y[0ll][i];
			x2 = x[1ll][i];
			y2 = y[1ll][i];
			cnt -= get(x1, y1, x2, y2, div, 0ll);
			cnt += get(x1, y1, x2, y2, div, 1ll);
			cnt1 += get(x1, y1, x2, y2, div, 0ll);
			cnt1 -= get(x1, y1, x2, y2, div, 1ll);
		}
		ans = min(ans, cnt);
		ans = min(ans, cnt1);
	}
}
main()
{
	cin >> n >> k;
	for(int i = 1ll;i <= k; i++){
		scanf("%lld%lld%lld%lld", &x[0ll][i], &y[0ll][i], &x[1ll][i], &y[1ll][i]);
	}
	//x1 = x[0ll][1];
	//y1 = y[0ll][1];
	//x2 = x[1ll][1];
	//y2 = y[1ll][1];
	//cout << get(x1, y1, x2, y2, 3ll, 0ll);
	if(n % 2ll == 1ll){
	  int x1, y1, x2, y2;
		int cnt = n * n / 2ll + 1ll, cnt1 = n * n / 2ll;
		for(int i = 1;i <= k; i++){
			x1 = x[0ll][i];
			y1 = y[0ll][i];
			x2 = x[1ll][i];
			y2 = y[1ll][i];
			cnt -= get(x1, y1, x2, y2, 1ll, 0ll);
			cnt += get(x1, y1, x2, y2, 1ll, 1ll);
			cnt1 += get(x1, y1, x2, y2, 1ll, 0ll);
			cnt1 -= get(x1, y1, x2, y2, 1ll, 1ll);
		}
		ans = min(ans, cnt);
		ans = min(ans, cnt1);
	}
	else{
		int x1, y1,x2, y2;
		int cnt = n * n / 2ll, cnt1 = n * n / 2ll;
		for(int i = 1;i <= k; i++){
			x1 = x[0ll][i];
			y1 = y[0ll][i];
			x2 = x[1ll][i];
			y2 = y[1ll][i];
			cnt -= get(x1, y1, x2, y2, 1ll, 0ll);
			cnt += get(x1, y1, x2, y2, 1ll, 1ll);
			cnt1 += get(x1, y1, x2, y2, 1ll, 0ll);
			cnt1 -= get(x1, y1, x2, y2, 1ll, 1ll);
		}
		ans = min(ans, cnt);
		ans = min(ans, cnt1);
	}
	for(int i = 2ll;i * i <= n; i++){
		if(n % i == 0ll){
			calc(i);
			calc(n / i);
		}
	}
	cout << ans;
}
/*
6 5
3 3 4 4
1 2 1 2
5 5 5 5
2 1 2 1
3 6 3 6
*/

Compilation message (stderr)

chessboard.cpp: In function 'long long int get(long long int, long long int, long long int, long long int, long long int, long long int)':
chessboard.cpp:22:17: warning: unused variable 'odd' [-Wunused-variable]
  int res = 0ll, odd, even;
                 ^~~
chessboard.cpp:22:22: warning: unused variable 'even' [-Wunused-variable]
  int res = 0ll, odd, even;
                      ^~~~
chessboard.cpp: At global scope:
chessboard.cpp:125:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^
chessboard.cpp: In function 'int main()':
chessboard.cpp:129:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld%lld%lld%lld", &x[0ll][i], &y[0ll][i], &x[1ll][i], &y[1ll][i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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