Submission #418864

#	Time	Username	Problem	Language	Result	Execution time	Memory
418864		JerryLiu06	Combo (IOI18_combo)	C++17	100 / 100	40 ms	572 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
 
using namespace std;
 
using ll = long long;
using ld = long double;
using db = double;
using str = string;
 
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;
 
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>;
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>;
using vpd = vector<pd>;
 
#define mp make_pair
#define f first
#define s second
 
#define sz(x) (int)(x).size()
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define sor(x) sort(all(x))
#define ft front()
#define bk back()
#define pb push_back
#define pf push_front
 
#define lb lower_bound
#define ub upper_bound
 
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define EACH(a,x) for (auto& a: x)
 
const int MOD = 1e9 + 7;
const int MX = 2010;
const ll INF = 1e18;
 
//bool press(string S) {}
 
vector<string> C {"A", "B", "X", "Y"};
 
string guess_sequence(int N) {
    string ans; // Get first letter in O(2) guesses
 
    if (press("AB")) { if (press("A")) ans = "A"; else ans = "B"; } 
 
    else { if (press("X")) ans = "X"; else ans = "Y"; } C.erase(find(all(C), ans));
 
    FOR(len, 1, N - 1) {
        string NEW = ans + C[2] + ans + C[1] + C[0] + ans + C[1] + C[1] + ans + C[1] + C[2];
 
        int X = press(NEW); if (X == len) ans += C[0]; else if (X == len + 1) ans += C[2]; else ans += C[1];
    }
    return N == 1 ? ans : (press(ans + C[0]) == N ? (ans + C[0]) : (press(ans + C[1]) == N ? (ans + C[1]) : (ans + C[2])));
}

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