Submission #866706

#	Time	Username	Problem	Language	Result	Execution time	Memory
866706		MercubytheFirst	Combo (IOI18_combo)	C++14	100 / 100	16 ms	1740 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:26:25: 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