Submission #982005

#	Time	Username	Problem	Language	Result	Execution time	Memory
982005		mariaclara	Combo (IOI18_combo)	C++17	100 / 100	15 ms	1920 KiB

combo

#include "combo.h"
#include<bits/stdc++.h>

using namespace std;

string guess_sequence(int N) {
    string prefix;
    vector<string> l;

    if(N == 1) {
        if(press("A")) return "A";
        if(press("B")) return "B";
        if(press("X")) return "X";
        return "Y";
    }

    if(press("AB")) {
        if(press("B")) prefix = "B", l = {"A","X","Y"};
        else prefix = "A", l = {"B","X","Y"};
    }
    else {
        if(press("X")) prefix = "X", l = {"A","B","Y"};
        else prefix = "Y", l = {"A","B","X"};
    }

    for(int i = 2; i < N; i++) {
        string query = prefix + l[0];
        query += prefix + l[1] + l[0];
        query += prefix + l[1] + l[1];
        query += prefix + l[1] + l[2];
        int ans = press(query);
        if(ans == i) prefix += l[0];
        else if(ans == i+1) prefix += l[1];
        else prefix += l[2];
    }

    if(press(prefix + l[0]) == N) {
        //cout << prefix + l[0];
        return prefix + l[0];
    }
    if(press(prefix + l[1]) == N) {
        //cout << prefix + l[1];
        return prefix + l[1];
    }
    //cout << prefix + l[2];
    return prefix + l[2];
}

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