Submission #1159263

#	Time	Username	Problem	Language	Result	Execution time	Memory
1159263		Der_Vlapos	Monochrome Points (JOI20_monochrome)	C++20	4 / 100	1 ms	328 KiB

monochrome

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define pii pair<int, int>
#define f first
#define s second
#define all(v) v.begin(), v.end()

// #define int ll

const int mod1 = 1e9 + 7;
const int mod2 = 998244353;

struct test
{
	void solve()
	{
		int n;
		cin >> n;
		vector<int> b, w;
		int bfk = 0;
		int cnt1 = 0, cnt2 = 0;
		for (int i = 0; i < 2 * n; ++i)
		{
			char x;
			cin >> x;
			if (x == 'B')
			{
				b.pb(i);
				cnt1++;
			}
			else
			{
				w.pb(i);
				cnt2++;
			}
			if (cnt1 == cnt2)
				bfk++;
		}

		int res = 0;
		for (int wtf = bfk - 10; wtf < bfk + 10; ++wtf)
		{
			int k = (wtf + 100 * n) % n;
			vector<pii> segs;
			for (int i = 0; i < n; ++i)
				segs.pb({min(b[i], w[(i + k) % n]), max(b[i], w[(i + k) % n])});

			sort(all(segs));
			int cnt = 0;
			for (int i = 0; i < n; ++i)
				for (int j = i + 1; j < n; ++j)
				{
					cnt += (segs[j].f < segs[i].s and segs[i].s < segs[j].s);
				}
			res = max(res, cnt);
		}

		cout << res << "\n";
	}
};

main()
{
	test t;
	t.solve();
}

Compilation message (stderr)

monochrome.cpp:66:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   66 | main()
      | ^~~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 21
• Subtask 3: 0 / 10
• Subtask 4: 0 / 65