Submission #342298

#	Time	Username	Problem	Language	Result	Execution time	Memory
342298		DrearyJoke	Combo (IOI18_combo)	C++17	100 / 100	48 ms	636 KiB

combo

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include "combo.h"
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<bool> vb;
typedef tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;

template <typename T, typename U> std::istream&operator>>(std::istream&i, pair<T,U>&p) {i >> p.x >> p.y; return i;}
template<typename T>std::istream&operator>>(std::istream&i,vector<T>&t) {for(auto&v:t){i>>v;}return i;}
template <typename T, typename U> std::ostream&operator<<(std::ostream&o, const pair<T,U>&p) {o << p.x << ' ' << p.y; return o;}
template<typename T>std::ostream&operator<<(std::ostream&o,const vector<T>&t) {if(t.empty())o<<'\n';for(size_t i=0;i<t.size();++i){o<<t[i]<<" \n"[i == t.size()-1];}return o;}

#define deb(x) cout << '>' << #x << ':' << x << endl;
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define END '\n'
#define inf 9e18
#define ff first
#define ss second
#define pb push_back


string guess_sequence(int n) {
    string s, p;
    int a = press("AABB");
    char first;
    if (a) {
        int ret = press("A");
        if (ret) first = 'A';
        else first = 'B'; 
    } else {
        int ret = press("X");
        if (ret) first = 'X';
        else first = 'Y';
    }
    s += first;
    if (n == 1) return s;
    int k = 0;
    char B[4] = {'A', 'B', 'X', 'Y'}, A[3];
    for (int i = 0; i < 4; ++i) {
        if (B[i] != first) A[k++] = B[i];
    }
    for (int i = 1; i < n - 1; ++i) {
        p = s + A[0] + s + A[1] + A[0] + s + A[1] + A[1] + s + A[1] + A[2];
        int ret = press(p);
        char nxt;
        if (ret == i) nxt = A[2];
        else if (ret == i + 1) nxt = A[0];
        else nxt = A[1];
        s += nxt; 
    }
    a = press(s + 'A' + s + 'B');
    if (a == n) {
        int ret = press(s + 'A');
        if (ret == n) first = 'A';
        else first = 'B'; 
    } else {
        int ret = press(s + 'X');
        if (ret == n) first = 'X';
        else first = 'Y';
    }
    s += first;
    // cout << s << END;
    return s;    
}

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