Submission #1015905

#	Time	Username	Problem	Language	Result	Execution time	Memory
1015905		deera	Combo (IOI18_combo)	C++14	100 / 100	18 ms	2168 KiB

combo

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

int press(string p);
#include "combo.h"


string guess_sequence(int N) {
    int a = press("AB");
    int b = press("BX");

    string f = "";

    if (a == 2) a--;
    if (b == 2) b--;

    if (a == 1 && b == 1) {
        f += "B";
    }
    if (a == 1 && b == 0) {
        f += "A";
    }
    if (a == 0 && b == 1) {
        f += "X";
    }
    if (a == 0 && b == 0) {
        f += "Y";
    }

    if (f.size() == N) {
        return f;
    }

    vector<string> r;

    if (f != "A") r.push_back("A");
    if (f != "B") r.push_back("B");
    if (f != "X") r.push_back("X");
    if (f != "Y") r.push_back("Y");

    while (true) {
        string g = f +  r[0] + f + r[1] + r[0] + f + r[1] + r[1] + f + r[1] + r[2];
        
        if (g.size() > N * 4) {
            break;
        } else {
            int p = press(g);
            if (p == f.size()) {
                f += r[2];
            } else if (p == f.size() + 1) {
                f += r[0];
            } else if (p == f.size() + 2) {
                f += r[1];
            }
        }
    }

    // guessing the last character
    int x = press(f + r[0] + f + r[1]) - f.size();
    int y = press(f + r[0] + f + r[2]) - f.size();

    if (x == 1 && y == 1) {
        f += r[0];
    }
    if (x == 1 && y == 0) {
        f += r[1];
    }
    if (x == 0 && y == 1) {
        f += r[2];
    }
    if (x == 0 && y == 0) {
        // shouldn't happen
    }

    return f;

}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:30:18: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   30 |     if (f.size() == N) {
      |         ~~~~~~~~~^~~~
combo.cpp:44:22: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   44 |         if (g.size() > N * 4) {
      |             ~~~~~~~~~^~~~~~~
combo.cpp:48:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |             if (p == f.size()) {
      |                 ~~^~~~~~~~~~~
combo.cpp:50:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |             } else if (p == f.size() + 1) {
      |                        ~~^~~~~~~~~~~~~~~
combo.cpp:52:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |             } else if (p == f.size() + 2) {
      |                        ~~^~~~~~~~~~~~~~~

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