Submission #490789

#	Time	Username	Problem	Language	Result	Execution time	Memory
490789		CyberSleeper	Combo (IOI18_combo)	C++14	100 / 100	39 ms	560 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
#define pb push_back
using namespace std;

int press(std::string p);

string ch="ABXY", opt="XYBA";
int in;

void ask(string s){
    in=press(s);
}

string guess_sequence(int N) {
    string S, tmp;
    ask("AB");
    if(in){
        ask("A");
        S=(in?"A":"B");
    }else{
        ask("X");
        S=(in?"X":"Y");
    } // 2 queries
    ch="";
    for(auto i:opt)
        if(i!=S[0])
            ch.pb(i);
    for(int i=2; i<N; i++){
        ask(S+ch[0] + S+ch[1]+ch[0] + S+ch[1]+ch[1] + S+ch[1]+ch[2]);
        if(in==S.size()){
            S.pb(ch[2]);
        }else if(in==(S.size()+1)){
            S.pb(ch[0]);
        }else{
            S.pb(ch[1]);
        }
    }
    if(S.size()<N){
        ask(S+ch[0]);
        if(in==N)
            S.pb(ch[0]);
        else{
            ask(S+ch[1]);
            S.pb((in==N)?ch[1]:ch[2]);
        }
    }
    return S;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:31:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         if(in==S.size()){
      |            ~~^~~~~~~~~~
combo.cpp:33:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |         }else if(in==(S.size()+1)){
      |                  ~~^~~~~~~~~~~~~~
combo.cpp:39:16: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   39 |     if(S.size()<N){
      |        ~~~~~~~~^~

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