Submission #470612

#	Time	Username	Problem	Language	Result	Execution time	Memory
470612		cp_is_hard	Colors (BOI20_colors)	C++14	100 / 100	3 ms	456 KiB

Colors

#define wiwihorz
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma loop-opt(on)

#define rep(i, a, b) for(int i = a; i <= b; i++)
#define rrep(i, a, b) for(int i = b; i >= a; i--)
#define all(x) x.begin(), x.end()
#define ceil(a, b)

using namespace std;

#define INF 1000000000000000000
#define lld long double
#define int long long int
#define pii pair<int, int>
#define random mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count())

#ifdef wiwihorz
#define print(a...) kout("[" + string(#a) + "] = ", a)
void vprint(auto L, auto R) { while(L < R) cerr << *L << " \n"[next(L) == R], ++L;}
void kout() { cerr << endl; }
template<class T1, class ... T2> void kout(T1 a, T2 ... e) { cerr << a << " ", kout(e...); }
#else 
#define print(...)
#define vprint(...)
#endif
namespace solver {
	int n, cur, cnt;
	const int key = 4;
	int query(int x) {
		cout << "? " << x << endl;
		int ans; cin >> ans;
//		int ans = abs(cur - x) >= key;
		cur = x, cnt ++;
		return ans;		
	}
	void solve(int _n) {
		n = _n, cnt = 0, cur = 0;
		int x = 0, L = 0, R = n, yes = 0;
		while(R - L > 1) {
			int mid = (L + R) / 2;
			x += (yes ? -1 : 1) * mid;
			yes ^= 1, cur = min(cur, x);
			L = mid;
		}
		L = 0, R = n;
		cur = 1 - cur, yes = 0;
		query(cur);
		while(R - L > 1) {
			int mid = (L + R) / 2;
			int id = (yes ? -1 : 1);
			bool ans = query(cur + id * mid);
			yes ^= 1;
			if(ans) R = mid;
			else L = mid;
		}
		print(cnt);
		cout << "= " << R << endl;
	}
};
using namespace solver;
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	int n; cin >> n;
	solve(n);
	return 0;
}

Compilation message (stderr)

Colors.cpp:4: warning: ignoring '#pragma loop ' [-Wunknown-pragmas]
    4 | #pragma loop-opt(on)
      | 
Colors.cpp:21:13: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   21 | void vprint(auto L, auto R) { while(L < R) cerr << *L << " \n"[next(L) == R], ++L;}
      |             ^~~~
Colors.cpp:21:21: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   21 | void vprint(auto L, auto R) { while(L < R) cerr << *L << " \n"[next(L) == R], ++L;}
      |                     ^~~~

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 24 / 24
• Subtask 5: 33 / 33