Submission #1008233

#	Time	Username	Problem	Language	Result	Execution time	Memory
1008233		aParrot	Combo (IOI18_combo)	C++14	0 / 100	1 ms	344 KiB

combo

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

#define ll long long
#define vi vector<int>
#define pb push_back
#define coord pair<int, int>
const int MOD = 1e9 + 7;
const int MAXN = 1e3;
// int dp[MAXN];

string guess_sequence(int N) {
    // find first letter in 2 presses
    int res;
    res = press("AB");
    string f;
    if (res >= 1) {
        res = press("A");
        if (res == 1) {
            f = "A";
        } else {
            f = "B";
        }
    } else {
        res = press("X");
        if (res == 1) {
            f = "X";
        } else {
            f = "Y";
        }
    }

    if (N==1) {
      return f;
    }

    vector<string> chars = {"A", "B", "X", "Y"};
    chars.erase(find(chars.begin(), chars.end(), f));
    // cout << "left letters:" << endl;
    // for (string c : chars) {
    //   cout << c << endl;
    // }
    // cout << endl;

    string ans = f;
    for (int i=1; i<N-1; i++) {
        // chars has length 3
        // excluding last character from chars
        string g = ans + chars[0];
        g += ans + chars[1] + chars[0];
        g += ans + chars[1] + chars[1];
        g += ans + chars[1] + chars[2];
        res = press(g);
        if (res == (int)ans.length()) {
            ans += chars[2];
        } else if (res == (int)ans.length()+1) {
            ans += chars[0];
        } else {
            ans += chars[1];
        }
    }

    // guess last letter
    res = press(ans + chars[0] + ans + chars[1]);
    if (res == N) {
      res = press(ans + chars[0]);
      if (res == N) {
        ans += chars[0];
      } else {
        ans += chars[1];
      }
    } else {
      ans += chars[2];
    }

    cout << "My answer: " << ans << endl;
    return ans;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 95