Submission #297199

#	Time	Username	Problem	Language	Result	Execution time	Memory
297199		Aldas25	Combo (IOI18_combo)	C++14	100 / 100	33 ms	540 KiB

combo

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

using namespace std;

#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define REP(n) FOR(O, 1,(n))
#define f first
#define s second
#define pb push_back
typedef vector<int> vi;
typedef pair<int, int> pii;

std::string guess_sequence(int n) {
    string buttons = "ABXY";

    string ret = "";

    string ask;
    ask = "AB";
    int coins = press(ask);
    if (coins > 0) {
        ask = "A";
        coins = press(ask);
        if (coins > 0) ret = "A";
        else ret = "B";
    } else {
        ask = "X";
        coins = press(ask);
        if (coins > 0) ret = "X";
        else ret = "Y";
    }

    if (n == 1) return ret;

    string tmp = buttons;
    buttons = "";
    for (char c : tmp)
        if (c != ret[0])
            buttons += c;

    FOR(i, 1, n-2) {
        ask = "";
        FOR(j, 0, 2) ask += ret + buttons[0] + buttons[j];
        ask += ret + buttons[1];
        coins = press(ask);
        if (coins == i) ret += buttons[2];
        else if (coins == i+1) ret += buttons[1];
        else ret += buttons[0];
    }

    ask = ret + buttons[0] + ret + buttons[1];
    coins = press(ask);
   // cout << "  asked " << ask << "  got: " << coins << endl;
    if (coins == n-1) ret += buttons[2];
    else {
        ask = ret + buttons[0];
        coins = press(ask);
        if (coins == n) ret += buttons[0];
        else ret += buttons[1];
    }

    //cout << "ret = " << ret << endl;

    return ret;
}

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