Submission #1288614

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288614		azamurai	Red-blue table (IZhO19_stones)	C++20	42 / 100	141 ms	11584 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;
const int ogr = 50;
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 mx = 0;
	vector <pair<int,pair<int,int>>> maybe;
	for (int cntx = 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 <= n * m) {
				maybe.push_back(mp(cntx + cnty, mp(cntx, cnty)));
			}
		}
	}
	sort(maybe.begin(), maybe.end());
	reverse(maybe.begin(), maybe.end());
	int need_y = (n + 2) / 2;
	int need_x = (m + 2) / 2;
	for (int i = 0; i < min(Sz(maybe), ogr); i++) {
		pair <int,int> to = maybe[i].se;
		int Cntx = to.fi;
		int Cnty = to.se;
		int predict = maybe[i].fi;
		for (int i = 1; i <= n; i++ ) {
			for (int j = 1; j <= m; j++) {
				a[i][j] = '0';
				cnt[j] = 0;
				used[j] = 0;
			}
		}
		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] = '-';
			}
		}
		if (calc() == predict) {
			cout << predict << '\n';
			break;
		}
	}
	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: 17 / 17
• Subtask 2: 10 / 10
• Subtask 3: 0 / 16
• Subtask 4: 0 / 11
• Subtask 5: 15 / 15
• Subtask 6: 0 / 31