Submission #1174104

#	Time	Username	Problem	Language	Result	Execution time	Memory
1174104		wpdmd76	Combo (IOI18_combo)	C++20	100 / 100	9 ms	508 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
using ll = long long;
#define all(v) v.begin(), v.end()


string guess_sequence(int N){
    string a[4] = {"A", "B", "X", "Y"}; 
    string res = "";
    int ix;
    int l = press("AB");
    if(l != 0){
        l = press("A");
        if(l == 1){
            res = "A";
            ix = 0;
        }else{
            res = "B";
            ix = 1;
        }
    }else{
        l = press("X");
        if(l == 1){
            res = "X";
            ix = 2;
        }else{
            res = "Y";
            ix = 3;
        }
    }
    if(N == 1) return res;
    while(res.size() < N - 1){
        string tmp = "";
        tmp += res + a[(ix + 1) % 4] + a[(ix + 1) % 4];
        tmp += res + a[(ix + 1) % 4] + a[(ix + 2) % 4];
        tmp += res + a[(ix + 1) % 4] + a[(ix + 3) % 4];
        tmp += res + a[(ix + 2) % 4];
        int x = press(tmp);
        if(x == res.size()) res += a[(ix + 3) % 4];
        else if(x ==  res.size() + 1) res += a[(ix + 2) % 4];
        else res += a[(ix + 1) % 4];
    }
    int cnt = 0;
    for(int i = 0; i < 4; i++){
        if(ix == i) continue;
        if(cnt == 2) break;
        if(press(res + a[i]) == N){
            return res + a[i];
        }
        cnt++;
    }
    if(ix == 3) return res + a[2];
    else return res + a[3];
}

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