Submission #1271209

#	Time	Username	Problem	Language	Result	Execution time	Memory
1271209		mkkkkkkkk	Combo (IOI18_combo)	C++20	Compilation error	0 ms	0 KiB

combo

#include <bits/stdc++.h>

using namespace std;

string guess_sequence(int N)
{
    char c=NULL;
    int br=press("AB");
    if(br==1)
    {
        br=press("A");
        if(br==1)
            c='A';
        else
            c='B';
    }
    else
    {
        br=press("X");
        if(br==1)
            c='X';
        else
            c='Y';
    }
    string possible="";
    if(c!='A')
        possible.push_back('A');
    if(c!='B')
        possible.push_back('B');
        if(c!='X')
        possible.push_back('X');
        if(c!='Y')
        possible.push_back('Y');


    string res="";
    res.push_back(c);
    for(int i=1;i<N-1;i++)
    {
        string temp="";
        temp+=res;
        temp.push_back(possible[0]);
        temp.push_back(possible[0]);

        temp+=res;
        temp.push_back(possible[0]);
        temp.push_back(possible[1]);

        temp+=res;
        temp.push_back(possible[0]);
        temp.push_back(possible[2]);

        temp+=res;
        temp.push_back(possible[1]);

        br=press(temp);
        if(br==i+1)
        {
            res.push_back(possible[1]);
        }
        else if(br==i+2)
        {
            res.push_back(possible[0]);

        }
        else
        {
            res.push_back(possible[2]);
        }

    }

    br=press(res+"AB");

    if(br==1)
    {
        br=press(res+"A");
        if(br==N)
            res.push_back('A');
        else
            res.push_back('B');
    }
    else
    {
        br=press(res+"X");
        if(br==N)
            res.push_back('X');
        else
            res.push_back('Y');
    }
    return res;

}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:7:12: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null]
    7 |     char c=NULL;
      |            ^~~~
combo.cpp:8:12: error: 'press' was not declared in this scope
    8 |     int br=press("AB");
      |            ^~~~~