Submission #421267

#	Time	Username	Problem	Language	Result	Execution time	Memory
421267		jlallas384	Combo (IOI18_combo)	C++17	100 / 100	37 ms	596 KiB

combo

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

using namespace std;

string guess_sequence(int n){
    string s = string(n,' ');
    if(press("AB")){
        if(press("A")) s[0] = 'A';
        else s[0] = 'B';
    }else{
        if(press("X")) s[0] = 'X';
        else s[0] = 'Y';
    }
    if(n == 1) return s;
    string c = "ABXY";
    c.erase(remove(c.begin(),c.end(),s[0]),c.end());
    for(int i = 1; i < n - 1; i++){
        string q = "";
        for(int j = 0; j < 3; j++){
            q += s.substr(0,i) + c[0] + c[j];
        }
        q += s.substr(0,i) + c[1];
        int res = press(q);
        if(res == i) s[i] = c[2];
        else if(res == i + 1) s[i] = c[1];
        else s[i] = c[0];
    }
    for(int i = 0; i < 2; i++){
        s[n-1] = c[i];
        if(press(s) == n) return s;
    }
    s[n-1] = c[2];
    return s;
}

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