Submission #1206949

#	Time	Username	Problem	Language	Result	Execution time	Memory
1206949		a1m4n	Combo (IOI18_combo)	C++20	100 / 100	6 ms	484 KiB

combo

#ifdef AIMAN
#define _GLIBCXX_DEBUG
#endif
#include "combo.h"
#include <bits/stdc++.h>
using namespace std;

string guess_sequence(int n) {
    string ans;
    int matched = 0;
    

    int x = press("AB");
    if (x == 0) {
        x = press("X");
        ans += (x == 1 ? 'X' : 'Y');
    } else {
        x = press("A");
        ans += (x == 1 ? 'A' : 'B');
    }
    matched = 1;


    while (matched + 2 <= n) {
        char s0 = ans[0];
        if (s0 == 'A') {
            x = press(ans + "BB" + ans + "BX" + ans + "BY" + ans + "X");
            ans += (x == matched   ? 'Y'
                 : (x == matched+1 ? 'X' : 'B'));
        }
        else if (s0 == 'B') {
            x = press(ans + "AA" + ans + "AX" + ans + "AY" + ans + "X");
            ans += (x == matched   ? 'Y'
                 : (x == matched+1 ? 'X' : 'A'));
        }
        else if (s0 == 'X') {
            x = press(ans + "AA" + ans + "AB" + ans + "AY" + ans + "B");
            ans += (x == matched   ? 'Y'
                 : (x == matched+1 ? 'B' : 'A'));
        }
        else { 
            x = press(ans + "BB" + ans + "BX" + ans + "BA" + ans + "X");
            ans += (x == matched   ? 'A'
                 : (x == matched+1 ? 'X' : 'B'));
        }
        matched++;
    }
    if (matched == n-1) {
        char s0 = ans[0];
        if (s0 == 'A') {
            x = press(ans + "B");
            if (x == n) ans += 'B';
            else {
                x = press(ans + "X");
                ans += (x == n ? 'X' : 'Y');
            }
        }
        else if (s0 == 'B') {
            x = press(ans + "A");
            if (x == n) ans += 'A';
            else {
                x = press(ans + "X");
                ans += (x == n ? 'X' : 'Y');
            }
        }
        else if (s0 == 'X') {
            x = press(ans + "A");
            if (x == n) ans += 'A';
            else {
                x = press(ans + "B");
                ans += (x == n ? 'B' : 'Y');
            }
        }
        else {
            x = press(ans + "B");
            if (x == n) ans += 'B';
            else {
                x = press(ans + "X");
                ans += (x == n ? 'X' : 'A');
            }
        }
    }

    return ans;
}

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