Submission #705623

#	Time	Username	Problem	Language	Result	Execution time	Memory
705623		garyye	Combo (IOI18_combo)	C++14	100 / 100	45 ms	608 KiB

combo

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

using namespace std;

int mpress(string s) {
    int g =  press(s);
//    cout << "Press " <<  s <<  " = " << g << endl;
    return g;
}

std::string guess_sequence(int N) {
    vector<char> c = {'A', 'B', 'X', 'Y'};

    string f = "";
    if(press("XY") > 0) {
        f = mpress("X") > 0 ? "X" : "Y";
    } else {
        f = mpress("A") > 0 ? "A" : "B";
    }

    if(N == 1) {
        return f;
    }

    c.erase(find(c.begin(), c.end(), f[0]));
   // A.   -> 1
   // BA.  -> 2
   // BB.  -> 2
   // BC.  -> 2

   // B. -> 1
   // CA -> 2
   // CB -> 2
    for(int i = 1; i < N - 1; ++i) {
        string s = "";
        s += f + c[0];
        s += f + c[1] + c[0];
        s += f + c[1] + c[1];
        s += f + c[1] + c[2];
        int g = mpress(s) - i;
        if(g == 0) f += c[2];
        if(g == 1) f += c[0];
        if(g == 2) f += c[1];
//        cout << "f = " << f << endl;
    }

    // 2 + (N - 2) calls done
    if(mpress(f + c[0]) == N)  return f + c[0];
    if(mpress(f + c[1]) == N)  return f + c[1];
    return f + c[2];
}

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