Submission #604890

#	Time	Username	Problem	Language	Result	Execution time	Memory
604890		boris_mihov	Combo (IOI18_combo)	C++14	100 / 100	37 ms	556 KiB

combo

#include <iostream>
#include "combo.h"

char let[4] = {'A', 'B', 'X', 'Y'};
std::string ans, guess;
std::string guess_sequence(int n) 
{
    int res = press("AB"), letIdx;
    if (res)
    {
        if (press("A")) ans = "A", letIdx = 0;
        else ans = "B", letIdx = 1;
    } else
    {
        if (press("X")) ans = "X", letIdx = 2;
        else ans = "Y", letIdx = 3;
    }

    if (n == 1) return ans;
    std::swap(let[letIdx], let[3]);
    for (int i = 2 ; i <= n-1 ; ++i)
    {
        guess = ans; guess += let[0];
        guess += ans + let[1] + let[0];
        guess += ans + let[1] + let[1];
        guess += ans + let[1] + let[2];
        int res = press(guess);
        if (res == i) ans += let[0];
        if (res == i+1) ans += let[1];
        if (res == i-1) ans += let[2];
    }

    guess = ans + let[0];
    if (press(guess) == n) return ans += let[0];

    guess = ans + let[1];
    if (press(guess) == n) return ans += let[1];
    return ans += let[2];
}

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