Submission #107609

#	Time	Username	Problem	Language	Result	Execution time	Memory
107609		FiloSanza	Combo (IOI18_combo)	C++14	97 / 100	69 ms	700 KiB

combo

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

using namespace std;

string guess_sequence(int N) {
    vector<char> v = {'A', 'B', 'X', 'Y'};
    random_shuffle(v.begin(), v.end());
    string sol = "";

    //First char
    if(press("A") == 1) sol = "A";
    else if(press("B") == 1) sol = "B";
    else if(press("X") == 1) sol = "X";
    else sol = "Y";

    v.erase(find(v.begin(), v.end(), sol[0]));

    if(N == 1) return sol;

    string tmp;
    while(true){
        if(sol.size() == N-1){
            if(press(sol+v[0]) == N) return sol+v[0];
            if(press(sol+v[1]) == N) return sol+v[1];
            return sol+v[2];
        }

        tmp = (sol + v[0]) + (sol + v[1] + v[2]) + (sol + v[1] + v[0]) + (sol + v[1] + v[1]);
        assert(tmp.size() <= 4*N);
        int coins = press(tmp);
        
        if(coins == sol.size() + 1) sol += v[0];
        else if(coins == sol.size() + 2) sol += v[1];
        else sol += v[2];

    }
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:23:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   23 |         if(sol.size() == N-1){
      |            ~~~~~~~~~~~^~~~~~
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:30:27: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   30 |         assert(tmp.size() <= 4*N);
      |                ~~~~~~~~~~~^~~~~~
combo.cpp:33:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |         if(coins == sol.size() + 1) sol += v[0];
      |            ~~~~~~^~~~~~~~~~~~~~~~~
combo.cpp:34:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         else if(coins == sol.size() + 2) sol += v[1];
      |                 ~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 92 / 95