Submission #127675

#	Time	Username	Problem	Language	Result	Execution time	Memory
127675		Shush	Combo (IOI18_combo)	C++17	97 / 100	79 ms	2476 KiB

combo

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

vector<char> b = {'A', 'B', 'X', 'Y'};

string guess_sequence(int N) {
	int n = N;
	string p = "";
	for(int i = 0; i < 3; i++){
		if(press(p + b[i])) {
			p += b[i];
			b.erase(b.begin() + i);
			break;
		}
	}
	if(p == ""){
		p += b[3];
		b.erase(b.begin() + 3);
	}
	for(int i = 1; i < n - 1; i++){
		int x = press(p + b[0] + p + b[1] + b[0] + p + b[1] + b[1] + p + b[1] + b[2]) - p.size();
		if(x == 0) p+= b[2];
		if(x == 1) p+= b[0];
		if(x == 2) p+= b[1];
		cerr << p << "\n";
	}
	if(n > 1){
	for(int i = 0; i < 2; i++){
		cerr << p + b[i] << "\n";
		if(press(p + b[i]) - p.size()) return p + b[i];
	}
	cerr << p + b[2] << "\n";
	return p + b[2];
	}
	return p;
}

• Subtask 1: 5 / 5
• Subtask 2: 92 / 95