Submission #1077354

#	Time	Username	Problem	Language	Result	Execution time	Memory
1077354		asdasdqwer	Combo (IOI18_combo)	C++14	30 / 100	31 ms	968 KiB

combo

#include "combo.h"

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

std::string guess_sequence(int N) {
    string ret;
    int f1 = press("AB");
    if (f1 == 0) {
        f1 = press("X");
        if (f1 == 1) ret += "X";
        else ret += "Y";
    }

    else if (f1 == 1) {
        f1 = press("B");
        if (f1 == 1) ret = "B";
        else ret = "A";
    }

    else ret = "AB";

    vector<string> possible = {"A", "B", "X", "Y"};
    possible.erase(std::find(possible.begin(), possible.end(), string(1, ret[0])));
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    while (ret.size() != N) {
        shuffle(possible.begin(), possible.end(), rng);
        int news = press(ret + possible[0] + ret + possible[1]);

        if (news == ret.size()) {
            ret += possible.back();
        }

        else {
            news = press(ret + possible[0]);
            if (news == ret.size()) ret += possible[1];
            else ret += possible[0];
        }
    }

    return ret;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:26:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   26 |     while (ret.size() != N) {
      |            ~~~~~~~~~~~^~~~
combo.cpp:30:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |         if (news == ret.size()) {
      |             ~~~~~^~~~~~~~~~~~~
combo.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |             if (news == ret.size()) ret += possible[1];
      |                 ~~~~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95