Submission #891314

#	Time	Username	Problem	Language	Result	Execution time	Memory
891314		presko	Combo (IOI18_combo)	C++14	100 / 100	13 ms	1912 KiB

combo

#include "combo.h"
//#include<iostream>
std::string guess_sequence(int N)
{
    char poss[4];
    std::string s="",p="";
    char first,use1,use2,use3;
    p="AB";
    poss[0]='A';
    poss[1]='B';
    poss[2]='X';
    poss[3]='Y';
    int res=press(p);
    if(res>=1)
    {
        p="A";
        res=press(p);
        if(res==1)s="A";
        else s="B";
    }
    else
    {
        p="X";
        res=press(p);
        if(res==1)s="X";
        else s="Y";
    }
    if(N==1)return s;

    p="";
    first=s[0];
    if(first=='A'){use1='B';use2='X';use3='Y';}
    else
    {
        use1='A';
        if(first=='B'){use2='X';use3='Y';}
        else
        {
            use2='B';
            if(first=='X')use3='Y';
            else use3='X';
        }
    }
    //std::cout<<s<<"_s "<<use1<<" "<<use2<<" "<<use3<<"\n";

    int prev=res;
    for(int i=1;i<N-1;i++)
    {
        p=s+use1;
        std::string curr="";
        for(int j=0;j<4;j++)
        {
            if(poss[j]!=first)curr=curr+s+use2+poss[j];
        }
        p=p+curr;
        //std::cout<<p<<" ";
        int ret=press(p);
        //std::cout<<ret<<"r\n";
        if(ret-i==0)s=s+use3;
        else if(ret-i==1)s=s+use1;
        else s=s+use2;
        //std::cout<<s<<"_s\n";
        prev=ret;
    }

    p=s+use1;
    res=press(p);
    if(res>N-1)s=s+use1;
    else
    {
        p=s+use2;
        res=press(p);
        if(res>N-1)s=s+use2;
        else s=s+use3;
    }

    return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:46:9: warning: variable 'prev' set but not used [-Wunused-but-set-variable]
   46 |     int prev=res;
      |         ^~~~

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