Submission #866704

#	Time	Username	Problem	Language	Result	Execution time	Memory
866704		vjudge1	Combo (IOI18_combo)	C++17	100 / 100	14 ms	1960 KiB

combo

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

// int press(string s){
//     return 1;
// }

string guess_sequence(int n){
    vector<char>buttons = {'A','B','X','Y'};
    char starting_char = '0';
    if(press("AB")){
        if(press("A"))
            starting_char = 'A';
        else
            starting_char = 'B';
    }
    else{
        if(press("X"))
            starting_char = 'X';
        else
            starting_char = 'Y';
    }
    string ans{starting_char};
    buttons.erase(find(buttons.begin(), buttons.end(), starting_char));
    if(ans.length() == n)
        return ans;

    // s + B + s + XY + s + XB + s + XX -> if starting_char == A
    for(int i = 1; i < n - 1; ++i){
        int current_coins = press(ans + string{buttons[0]} + ans + string{buttons[1],buttons[0]} + ans
                                   + string{buttons[1], buttons[1]} + ans + string{buttons[1], buttons[2]});
        if(current_coins == i)
            ans.push_back(buttons[2]);
        else if(current_coins == i + 1)
            ans.push_back(buttons[0]);
        else if(current_coins == i + 2)
            ans.push_back(buttons[1]);
    }

    if(press(ans + string{buttons[0]} + ans + string{buttons[1]}) == n){
        if(press(ans + string{buttons[0]}) == n)
            ans.push_back(buttons[0]);
        else
            ans.push_back(buttons[1]);

    }
    else{
        ans.push_back(buttons[2]);
    }
    return ans;


}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:26:21: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   26 |     if(ans.length() == n)
      |        ~~~~~~~~~~~~~^~~~

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