Submission #1008383

#	Time	Username	Problem	Language	Result	Execution time	Memory
1008383		HappyCapybara	Combo (IOI18_combo)	C++17	100 / 100	27 ms	1932 KiB

combo

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

string guess_sequence(int N){
    string s;
    if (press("AB")){
        if (press("A")) s = "A";
        else s = "B";
    }
    else {
        if (press("X")) s = "X";
        else s = "Y";
    }
    if (N == 1) return s;
    vector<string> v;
    for (string x : {"A", "B", "X", "Y"}) if (s != x) v.push_back(x);
    while (s.size() < N-1){
        string p;
        p += s;
        p += v[0];
        for (int i=0; i<3; i++){
            p += s;
            p += v[1];
            p += v[i];
        }
        int res = press(p);
        if (res == s.size()+1) s += v[0];
        else if (res == s.size()+2) s += v[1];
        else s += v[2];
    }
    if (press(s+v[0]) == N) return s+v[0];
    if (press(s+v[1]) == N) return s+v[1];
    return s+v[2];
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:18:21: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   18 |     while (s.size() < N-1){
      |            ~~~~~~~~~^~~~~
combo.cpp:28:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |         if (res == s.size()+1) s += v[0];
      |             ~~~~^~~~~~~~~~~~~
combo.cpp:29:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |         else if (res == s.size()+2) s += v[1];
      |                  ~~~~^~~~~~~~~~~~~

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