Submission #1072427

#	Time	Username	Problem	Language	Result	Execution time	Memory
1072427		andrewp	Combo (IOI18_combo)	C++14	100 / 100	23 ms	1400 KiB

combo

//Dedicated to my love, ivaziva
#include "combo.h"  
#include <bits/stdc++.h>
using namespace std; 

using pii = pair<int, int>;
using ll = int64_t;

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define dbg(x) cerr << #x << ": " << x << '\n';  

string guess_sequence(int n) {
    char f;
    if (press("AB")) {
        if (press("A")) 
            f = 'A';
        else 
            f = 'B';
    } else {
        if (press("Y") == 1)
            f = 'Y';
        else 
            f = 'X';
    }
    string ans = "";
    ans.push_back(f);
    int sz = 1;
    for (int i = 2; i < n; i++) {
        if (f == 'A') {
            int ret = press(ans + "Y" + ans + "XX" + ans + "XY" + ans + "XB");
            if (ret == sz + 1)
                ans.push_back('Y');
            else if (ret == sz + 2)
                ans.push_back('X');
            else 
                ans.push_back('B');
        } else if (f == 'B') {
            int ret = press(ans + "Y" + ans + "XX" + ans + "XY" + ans + "XA");
            if (ret == sz + 1)
                ans.push_back('Y'); 
            else if (ret == sz + 2)
                ans.push_back('X');
            else 
                ans.push_back('A'); 
        } else if (f == 'X') {
            int ret = press(ans + "Y" + ans + "AA" + ans + "AY" + ans + "AB");
            if (ret == sz + 1)
                ans.push_back('Y');
            else if (ret == sz + 2)
                ans.push_back('A');
            else 
                ans.push_back('B');

        } else if (f == 'Y') {
            int ret = press(ans + "X" + ans + "AX" + ans + "AA" + ans + "AB");
            if (ret == sz + 1)
                ans.push_back('X');
            else if (ret == sz + 2)
                ans.push_back('A');
            else 
                ans.push_back('B'); 
        }
        sz++;
    }
    if (sz == n) {
        return ans;
    }
    if (f == 'A') {
        if (press(ans + 'X') == n) 
            ans.push_back('X');
        else if (press(ans + 'Y') == n) 
            ans.push_back('Y');
        else
            ans.push_back('B'); 
    } else if (f == 'B') { 
        if (press(ans + 'X') == n) 
            ans.push_back('X');
        else if (press(ans + 'Y') == n) 
            ans.push_back('Y');
        else
            ans.push_back('A');  
    } else if (f == 'X') { 
        if (press(ans + 'Y') == n) 
            ans.push_back('Y');
        else if (press(ans + 'B') == n) 
            ans.push_back('B');
        else
            ans.push_back('A');  
    } else if (f == 'Y') {  
        if (press(ans + 'A') == n) 
            ans.push_back('A');
        else if (press(ans + 'X') == n) 
            ans.push_back('X');
        else
            ans.push_back('B');  
    }
    return ans; 
}

/*int32_t main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    cout.tie(nullptr); cerr.tie(nullptr);
    

    return 0;
}*/

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