Submission #1272267

#	Time	Username	Problem	Language	Result	Execution time	Memory
1272267		jungle15	Combo (IOI18_combo)	C++17	5 / 100	1 ms	400 KiB

combo

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

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

#define Jungle "IOI18_combo"
#define getbit(x, i) (((x) >> (i)) & 1)
#define MASK(i) (1 << (i))
#define cntbit __builtin_popcount

template <typename t>
void chkmin(t &a, t b)
{
    if (a > b) a = b;
}

template <typename t>
void chkmax(t &a, t b)
{
    if (a < b) a = b;
}

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";
    }
    vector<char> rem;
    for (char c : {'A','B','X','Y'})
        if (c != ans[0]) rem.push_back(c);
    char b = rem[0], x = rem[1], y = rem[2];
    for (int i = 1; i < N-1; i++) {
        string q;
        q.reserve(ans.size()*4+10);
        q += ans;
        q.push_back(b);
        q += ans;
        q.push_back(x); q.push_back(b);
        q += ans;
        q.push_back(x); q.push_back(x);
        q += ans;
        q.push_back(x); q.push_back(y);
        int res = press(q);
        if (res == (int)ans.size()+1)
            ans.push_back(b);
        else if (res == (int)ans.size()+2)
            ans.push_back(x);
        else
            ans.push_back(y);
    }
    for (char c : {b,x,y})
        if (press(ans + c) == N) {
            ans.push_back(c);
            break;
        }
    return ans;
}

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