Submission #256342

#	Time	Username	Problem	Language	Result	Execution time	Memory
256342		SpeedOfMagic	Combo (IOI18_combo)	C++17	100 / 100	36 ms	548 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
#define sz(a) (int) a.size()
string guess_sequence(int N) {
	string ans = "";
	
	string l1 = "A", l2 = "B", l3 = "X";
	
	int c = press("AB");
	if (c) {
		c = press("A");
		if (c) {
			ans += "A";
			l1 = "Y";
		} else {
			ans += "B";
			l2 = "Y";
		}
	} else {
		c = press("X");
		if (c) {
			ans += "X";
			l3 = "Y";
		} else
			ans += "Y";
	}
	
	while (sz(ans) < N) {
		if (sz(ans) + 1 == N) {
			string v = ans + l1 + ans + l2;
			//cout << v << endl;
			c = press(v) - sz(ans);
			if (c) {
				v = ans + l1;
			//cout << v << endl;
				c = press(v) - sz(ans);
				if (c)
					ans += l1;
				else
					ans += l2;
			} else
				ans += l3;
		} else {
			string v = ans + l1 + l1 + ans + l1 + l2 + ans + l2 + l1;
			//cout << v << endl;
			c = press(v) - sz(ans);
			if (c == 0)
				ans += l3;
			else if (c == 1) {
				string v = ans + l2 + l2;
			//cout << v << endl;
				c = press(v) - sz(ans);
				if (c == 0)
					ans += l1 + l3;
				else if (c == 1)
					ans += l2 + l3;
				else
					ans += l2 + l2;
			} else {
				string v = ans + l1 + l1;
			//cout << v << endl;
				c = press(v) - sz(ans);
				if (c == 0)
					ans += l2 + l1;
				else if (c == 1)
					ans += l1 + l2;
				else
					ans += l1 + l1;
			}
		}
	}
	
	return ans;
}

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