Submission #114099

#	Time	Username	Problem	Language	Result	Execution time	Memory
114099		Alexa2001	Combo (IOI18_combo)	C++17	5 / 100	45 ms	576 KiB

combo

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

using namespace std;



string guess_sequence(int N)
{
    int ask1, ask2, ask3, ask4;
    char a, b, c, d;

    ask1 = press("AB");
    ask2 = (!ask1);
    ask3 = press("AX");
    ask4 = (!ask3);

    if(ask1 && ask3)              a = 'A', b = 'B', c = 'X', d = 'Y';
        else if(ask1 && ask4)     a = 'B', b = 'A', c = 'X', d = 'Y';
            else if(ask2 && ask3) a = 'X', b = 'A', c = 'B', d = 'Y';
                else              a = 'Y', b = 'A', c = 'B', d = 'X';

    string S;
    S.push_back(a);

    if(N == 1) return S;

    string s1, s2, s3, s4;
    s1.push_back(b);
    s2.push_back(c); s2.push_back(b);
    s3.push_back(c); s3.push_back(c);
    s4.push_back(c); s4.push_back(d);

    string p;
    while(S.size() + 2 <= N)
    {
        p = S + s1 + S + s2 + S + s3 + S + s4;
        assert(p.size() <= 4 * N);

        int coins = press(p);

        if(coins == S.size() + 1)
            S.push_back(b);
        else if(coins == S.size() + 2)
            S.push_back(c);
        else S.push_back(d);
    }

    p = S; p.push_back(b);
    if(press(p) == N) return p;

    p = S; p.push_back(c);
    if(press(p) == N) return p;

    p = S; p.push_back(d);
    return p;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:35:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   35 |     while(S.size() + 2 <= N)
      |           ~~~~~~~~~~~~~^~~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from combo.cpp:2:
combo.cpp:38:25: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   38 |         assert(p.size() <= 4 * N);
      |                ~~~~~~~~~^~~~~~~~
combo.cpp:42:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         if(coins == S.size() + 1)
      |            ~~~~~~^~~~~~~~~~~~~~~
combo.cpp:44:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |         else if(coins == S.size() + 2)
      |                 ~~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95