Submission #701043

#	Time	Username	Problem	Language	Result	Execution time	Memory
701043		BobCompetitiveProgramming	Combo (IOI18_combo)	C++14	30 / 100	41 ms	584 KiB

combo

#include <bits/stdc++.h>
using namespace std; using ll=long long;


int press(std::string p);

string getRandom(string start, string no, int sz){
    while(start.size() < sz){
        int r = rand() % 4 + 1;
        if(r==1 && "A" != no) start += "A";
        if(r==2 && "B" != no) start += "B";
        if(r==3 && "X" != no) start += "X";
        if(r==4 && "Y" != no) start += "Y";
    }
    return start; 
}

string guess_sequence(int N){
    string S = "", first, a1, a2, a3;
    if(press("AB")) {
        if(press("A")) first="A", S="A", a1="B", a2="X", a3="Y";
        else first="B", S="B", a1="A", a2="X", a3="Y";
    } else {
        if(press("X")) first="X", S="X", a1="B", a2="A", a3="Y";
        else first="Y", S="Y", a1="B", a2="X", a3="A";
    }

    vector<string> a{a1, a2, a3}; 

    auto randommize = [&](){
        random_shuffle(a.begin(), a.end());
        a1 = a[0];
        a2 = a[1];
        a3 = a[2];
    };
        
    while(true){
        int curr_size = S.size();
        if(curr_size == N) 
            return S; 
        
        randommize();

        if(press(S+a1+S+a2)>curr_size){
            if(press(S+a1)>curr_size) S+=a1;
            else S+=a2;
        } else
            S+=a3; 
    }   
}

Compilation message (stderr)

combo.cpp: In function 'std::string getRandom(std::string, std::string, int)':
combo.cpp:8:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
    8 |     while(start.size() < sz){
      |           ~~~~~~~~~~~~~^~~~

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95