Submission #1230759

#	Time	Username	Problem	Language	Result	Execution time	Memory
1230759		riddles	Combo (IOI18_combo)	C++20	100 / 100	7 ms	484 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
typedef long long ll;
typedef map<ll, ll> mp;
typedef pair<ll, ll> pll;
typedef queue<ll> qi;
typedef vector<ll> vi;
typedef vector<bool> vb;
typedef vector <vi> vvi;
typedef vector <pll> vpl;
typedef vector <string> vs;
#define YES cout<<"YES\n"
#define Yes cout<<"Yes\n"
#define NO cout<<"NO\n"
#define No cout<<"No\n"
#define F first
#define S second
#define pb push_back
#define all(x) begin(x), end(x)

string guess_sequence(int N) {
    string ans;
    if (press("AB")) {
        if (press("A")) ans = "A";
        else ans = "B";
    } else {
        if (press("X")) ans = "X";
        else ans = "Y";
    }

    if (N == 1) return ans;

    char p[3];
    int k = 0;
    for (char c : {'A', 'B', 'X', 'Y'}) {
        if (c != ans[0]) p[k++] = c;
    }

    for (int i = 1; i < N - 1; ++i) {
        string ask = ans + p[0] + ans + p[1] + p[0] + ans + p[1] + p[1] + ans + p[1] + p[2];
        int q = press(ask);
        if (q == i + 2) ans += p[1];
        else if (q == i + 1) ans += p[0];
        else ans += p[2];
    }

    if (press(ans + p[0]) == N) ans += p[0];
    else if (press(ans + p[1]) == N) ans += p[1];
    else ans += p[2];

    return ans;
}

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