Submission #246994

#	Time	Username	Problem	Language	Result	Execution time	Memory
246994		ernestvw	Combo (IOI18_combo)	C++17	100 / 100	44 ms	824 KiB

combo

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

#define sz(x) ((int)x.size())

int press(string p);

char find_first() {
	int q1 = press("AB");
	if(q1 > 0) {
		int q2 = press("A");
		if(q2 > 0) return 'A';
		return 'B';
	}
	int q2 = press("X");
	if(q2 > 0) return 'X';
	return 'Y';
}

string guess_sequence(int N) {
	string ans = "";

	char premier = find_first();
	ans += premier;

	vector<char> C;
	if('A' != premier) C.push_back('A');
	if('B' != premier) C.push_back('B');
	if('X' != premier) C.push_back('X');
	if('Y' != premier) C.push_back('Y');
	vector<string> D;
	for(char c1 : C) for(char c2 : C) {
		string p = "";
		p += c1;
		p += c2;
		D.push_back(p);
	}

	for(int i = 1; i < N - 1; ++i) {
		string p = "";
		vector<string> q(4, ans);
		
		for(int j = 0; j < 3; ++j) {
			q[j] += C[0];
			q[j] += C[j];
		}

		q[3] += C[1];

		for(string s : q) p += s;

		int x = press(p);

		if(x == i + 2)
			ans += C[0];
		else if(x == i + 1)
			ans += C[1];
		else
			ans += C[2];
	}

	if(N == 1) return ans;

	string p1 = ans;
	p1 += C[0];
	p1 += ans;
	p1 += C[1];

	int x = press(p1);
	if(x == N) {
		string p2 = ans;
		p2 += C[0];
		int y = press(p2);
		if(y == N) ans += C[0];
		else ans += C[1];
	}
	else ans += C[2];

	return ans;
}

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