Submission #1226978

#	Time	Username	Problem	Language	Result	Execution time	Memory
1226978		Hamed_Ghaffari	Combo (IOI18_combo)	C++17	100 / 100	7 ms	484 KiB

combo

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

string guess_sequence(int N) {
    string chs = "ABXY", ans;
    if(press("AB")) {
        if(press("A")) ans.push_back('A');
        else ans.push_back('B');
    }
    else if(press("X")) ans.push_back('X');
    else ans.push_back('Y');
    if(N==1) return ans;
    for(int i=0; i<4; i++)
        if(chs[i]==ans[0]) {
            swap(chs[i], chs.back());
            break;
        }
    chs.pop_back();
    for(int i=1; i+1<N; i++) {
        string ask = ans;
        ask.push_back(chs[0]);
        ask += ans;
        ask.push_back(chs[1]);
        ask.push_back(chs[0]);
        ask += ans;
        ask.push_back(chs[1]);
        ask.push_back(chs[1]);
        ask += ans;
        ask.push_back(chs[1]);
        ask.push_back(chs[2]);
        int res = press(ask);
        if(res==i) ans.push_back(chs[2]);
        else if(res==i+1) ans.push_back(chs[0]);
        else ans.push_back(chs[1]);
    }
    ans.push_back(chs[0]);
    if(press(ans)==N) return ans;
    ans.back() = chs[1];
    if(press(ans)==N) return ans;
    ans.back() = chs[2];
    return ans;
}

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