Submission #441094

#	Time	Username	Problem	Language	Result	Execution time	Memory
441094		beferith	Combo (IOI18_combo)	C++14	100 / 100	38 ms	680 KiB

combo

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

string guess_sequence(int N){
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

    vector<string> chr = {"A","B","X","Y"};

    string curr = "";
    
    for(int i=0;i<N;i++){
        shuffle(chr.begin(),chr.end(),rng);
        if(i == 0){
            int half = press("AB");
            if(half == 0){
                int quad = press("X");
                if(quad){
                    curr += "X";
                }else{
                    curr += "Y";
                }
            }else{
                int quad = press("A");
                if(quad){
                    curr += "A";
                }else{
                    curr += "B";
                }
            }
            chr.erase(find(chr.begin(),chr.end(),curr));
        }else if(i == N-1){
            bool found = false;
            for(int j=0;j<chr.size()-1;j++){
                if(press(curr + chr[j]) == i+1){
                    curr += chr[j];
                    found = true;
                    break;
                }
            }
            if(!found){
                curr += chr[chr.size()-1];
            }
        }else{
            string ask = (curr+chr[0]) + (curr+chr[1]+chr[0]) + (curr+chr[1]+chr[1]) + (curr+chr[1]+chr[2]);
            int query = press(ask);
            if(query == i){
                curr += chr[2];
            }else if(query == i+2){
                curr += chr[1];
            }else{
                curr += chr[0];
            }
        }
    }
    return curr;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:34:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |             for(int j=0;j<chr.size()-1;j++){
      |                         ~^~~~~~~~~~~~~

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