Submission #1235490

#	Time	Username	Problem	Language	Result	Execution time	Memory
1235490		nicolo_010	Combo (IOI18_combo)	C++20	100 / 100	7 ms	508 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
template <typename T>
using v = vector<T>;
using ll = long long;
using pii = pair<int, int>;
#define rep(i, k, n) for (int i=k; i < n; i++)

string guess_sequence(int N) {
	int n = N;
	string ans = "";
	int c = press("AB");
	if (c == 2) {
		ans += "A";
	}
	else if (c == 1) {
		c = press("A");
		if (c) ans += "A";
		else ans += "B";
	}
	else {
		c = press("X");
		if (c) {
			ans += 'X';
		}
		else {
			ans += "Y";
		}
	}
	set<char> s;
	s.insert('A'); s.insert('B'); s.insert('X'); s.insert('Y');
	s.erase(ans[0]);
	auto it = s.begin();
	if (n == 1) return ans;
	rep(i, 1, n-1) {
		string q = "";
		int cnt = 0;
		for (auto x : s) {
			string aux2 = ans + *it + x;
			q += aux2;
		}
		auto itaux = next(it);
		auto last = next(itaux);
		q += (ans + *itaux);
		c = press(q);
		if (c == i+2) {
			ans += *it;
		}
		else if (c == i+1) {
			ans += *itaux;
		}
		else {
			ans += *last;
		}
	}
	auto itnext = next(it);
	string query = ans + *it;
	query += ans + *itnext;
	c = press(query);
	if (c == n) {
		query = ans+*it;
		c = press(query);
		if (c == n) {
			ans += *it;
		}
		else {
			ans += *itnext;
		}
	}
	else {
		itnext = next(itnext);
		ans += *itnext;
	}
	return ans;
}

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