Submission #996983

#	Time	Username	Problem	Language	Result	Execution time	Memory
996983		TrendBattles	Combo (IOI18_combo)	C++14	100 / 100	20 ms	1524 KiB

combo

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

string guess_sequence(int N) {
    string choices = "ABXY";

    string ret = "";
    int pos = -1;
    if (press(string(1, choices[0]) + string(1, choices[1]))) {
        pos = press(string(1, choices[1]));
    } else {
        pos = 2 + press(string(1, choices[3]));
    }

    ret.push_back(choices[pos]);
    choices.erase(pos, 1);

    for (int i = 1; i < N; ++i) {
        if (i == N - 1) {
            pos = 2;
            for (int j : {0, 1}) {
                if (press(ret + choices[j]) == N){
                    pos = j; break;
                }
            }

            ret.push_back(choices[pos]);
            break;
        }

        string ask = "";
        ret.push_back(choices[0]);
        for (int j : {0, 1, 2}) {
            ret.push_back(choices[j]);
            ask += ret;
            ret.pop_back();
        }
        ret.pop_back(); ret.push_back(choices[1]);
        ask += ret; ret.pop_back();

        int len = press(ask);
        if (len == i + 2) {
            ret.push_back(choices[0]);
        } else if (len == i + 1) {
            ret.push_back(choices[1]);
        } else {
            ret.push_back(choices[2]);
        }
    }

    return ret;
}

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