Submission #1288611

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288611		azamurai	Red-blue table (IZhO19_stones)	C++20	15 / 100	25 ms	4412 KiB

stones

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define Sz(x) (int)x.size()

const int N = 1005;
int n, m, cnt[N], used[N];
char a[N][N];

int calc() {
	int res = 0;
	for (int i = 1; i <= n; i++) {
		int blue = 0, red = 0;
		for (int j = 1; j <= m; j++) {
			if (a[i][j] == '-') blue++;
			else red++;
		}
		if (red > blue) res++;
	}
	for (int j = 1; j <= m; j++) {
		int blue = 0, red = 0;
		for (int i = 1; i <= n; i++) {
			if (a[i][j] == '-') blue++;
			else red++;
		}
		if (blue > red) res++;
	}
	return res;
}

void solve() {
	cin >> n >> m;
	int Cntx, Cnty;
	int limit = n * m;
	if (n % 2 != m % 2) limit--;
	for (int cntx = 0, mx = 0; cntx <= n; cntx++) {
		for (int cnty = 0; cnty <= m; cnty++) {
			int red = cntx * ((m + 2) / 2);
			int blue = cnty * ((n + 2) / 2);
			if (red + blue <= limit && cntx + cnty > mx) {
				Cntx = cntx;
				Cnty = cnty;
				mx = cntx + cnty;
			}
		}
	}
	for (int i = 1; i <= n; i++ ) {
		for (int j = 1; j <= m; j++) {
			a[i][j] = '0';
			cnt[j] = 0;
			used[j] = 0;
		}
	}
	int need_y = (n + 2) / 2;
	int need_x = (m + 2) / 2;
	for (int i = 1; i <= Cntx; i++) {
		int amount = 0;
		for (int j = 1; j <= m; j++) {
			used[j] = 0;
		}
		for (int j = 1; j <= m; j++) {
			if (amount == need_x) break;
			if ((n - cnt[j]) < need_y) {
				amount++;
				cnt[j]++;
				used[j] = 1;
				a[i][j] = '+';
			}
		}
		if (amount == need_x) continue;
		vector <pair<int,int>> save;
		for (int j = 1; j <= m; j++) {
			if (used[j] || (n - cnt[j]) <= need_y) continue;
			save.push_back(mp(cnt[j], j));
		}
		sort(save.begin(), save.end());
		for (auto to : save) {
			if (amount == need_x) break;
			amount++;
			cnt[to.se]++;
			used[to.se] = 1;
			a[i][to.se] = '+';
		}
		if (amount == need_x) continue;
		for (int j = 1; j <= m; j++) {
			if (used[j] || (n - cnt[j]) != need_y || amount == need_x) continue;
			amount++;
			cnt[j]++;
			used[j] = 1;
			a[i][j] = '+';
		}
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			if (a[i][j] == '0') a[i][j] = '-';
		}
	}
	cout << calc() << '\n';
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			cout << a[i][j];
		}
		cout << '\n';
	}
}

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	int t = 1;
	cin >> t;
	
	for (int T = 1; T <= t; T++) {
		solve();
		//cout << '\n';
	}
}

• Subtask 1: 0 / 17
• Subtask 2: 0 / 10
• Subtask 3: 0 / 16
• Subtask 4: 0 / 11
• Subtask 5: 15 / 15
• Subtask 6: 0 / 31