Submission #690045

#	Time	Username	Problem	Language	Result	Execution time	Memory
690045		iskhakkutbilim	Red-blue table (IZhO19_stones)	C++14	32 / 100	2091 ms	3132 KiB

stones

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

//#define int long long
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
int n, m;
int calc(vector<vector<int> > &a){
	int all = 0;
	for(int i = 0;i < n; i++){
		int blue = 0;
		for(int j = 0;j < m; j++){
			blue+= a[i][j];
		}
		if(blue >= m-(m / 2) and blue > m/2) all++;
	}
	for(int j = 0;j < m; j++){
		int red = 0;
		for(int i = 0;i < n; i++){
			red+= (a[i][j] == 0);
		}
		if(red >= n-(n / 2) and red > n/2) all++;
	}
	return all;
}

void solve(){
	 cin >> n >> m;
	vector< vector<int> > a(n, vector<int>(m,0));
	int need = max(n / 2+1, n-(n / 2));
	 if(n == m){
	 	set<pair<int, int> > st;
		vector< pair<int, int> > del;
		for(int i = 0;i < m; i++){
			st.insert({0, i});
		}
		for(int i = 0;!st.empty() and i < n; i++){
			int cnt = need;
			for(pair<int, int> x : st){
				if(cnt == 0) break;
				cnt--;
				if(x.ff== n-need){
					st.clear();
					break;
				}
				a[i][x.ss] = 1;
				del.push_back(x);
			}
			for(pair<int, int> x : del){
				st.erase(x);
				st.insert({x.ff+1, x.ss});
			}
			del.clear();
		}
		cout << calc(a) << '\n';
		for(int i = 0;i < n; i++){
			for(int j = 0;j < m; j++){
				cout << (a[i][j] ? '+' : '-');
			}
			cout << '\n';
		}
	 	return;
	 }	
	int answer = 0, s = 0, MASK=0;
	vector<pair<int,int>> cell(n*m);
	for(int i = 0;i < n; i++){
		for(int j = 0;j < m; j++){
			cell[s] = {i, j};
			s++;
		}
	}
	for(int mask = 0; mask < (1<<(n*m)); mask++){
		for(int i = 0;i < n*m; i++){
			if(mask & (1<<i)){
				a[cell[i].ff][cell[i].ss] = 1;
			}else{
				a[cell[i].ff][cell[i].ss] = 0;
			}
		}
		int S = calc(a);
		
		if(answer < S){
			answer = S;
			MASK = mask;
		}
	}
	for(int i = 0;i < n*m; i++){
		if(MASK & (1<<i)){
			a[cell[i].ff][cell[i].ss] = 1;
		}else{
			a[cell[i].ff][cell[i].ss] = 0;
		}
	}
	cout << answer << '\n';
	for(int i = 0;i < n; i++){
		for(int j = 0;j < m; j++){
			cout << (a[i][j] ? '+' : '-'); 
		}
		cout << '\n';
	}
}


main(){
   ios::sync_with_stdio(0);
   cin.tie(0); cout.tie(0);
	int t; cin >> t;
	while(t--){
		solve();
//		cout << '\n';
	}

	return 0;
}

Compilation message (stderr)

stones.cpp:105:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  105 | main(){
      | ^~~~

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