Submission #916879

#	Time	Username	Problem	Language	Result	Execution time	Memory
916879		mpb_	Combo (IOI18_combo)	C++17	30 / 100	23 ms	1724 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>

std::string guess_sequence(int N) {
	using namespace std;
	auto guess = [&](string p) {
		return press(p);
	};
	vector<string> ch = {"A", "B", "X", "Y"};
	string fst = "?";
	for (int i = 0; i < 3; i++) {
		string p = ch[i];
		int coins = press(p);
		if (coins == 1) {
			fst = ch[i];
			break;
		}
	}
	if (fst == "?") {
		fst = "Y";
	}
	vector<string> nch = {};
	for (auto x : ch) {
		if (x != fst) nch.push_back(x);
	}
	string ans = fst;
	for (int i = 1; i < N; i++) {
		bool found = false;
		for (int j = 0; j < 2; j++) {
			string tmp = ans + nch[j];
			int coins = guess(tmp);
			if (coins == i + 1) {
				found = true;
				ans += nch[j];
				break;
			}
		}
		if (!found) {
			ans += nch[2];
		}
	}
	return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95