Submission #1029671

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029671		AmirAli_H1	Combo (IOI18_combo)	C++17	100 / 100	20 ms	1716 KiB

combo

// In the name of Allah

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

typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;

#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 2000 + 4;

int n; string res;

string guess_sequence(int Nx) {
	n = Nx; res = "";
	if (press("AB") >= 1) {
		if (press("A") >= 1) res += "A";
		else res += "B";
	}
	else {
		if (press("X") >= 1) res += "X";
		else res += "Y";
	}
	if (n == 1) return res;
	
	vector<char> ls;
	for (char ch : {'A', 'B', 'X', 'Y'}) {
		if (ch != res[0]) ls.pb(ch);
	}
	
	for (int i = 1; i < n - 1; i++) {
		string s = "";
		s += res; s += ls[0];
		s += res; s += ls[1]; s += ls[0];
		s += res; s += ls[1]; s += ls[1];
		s += res; s += ls[1]; s += ls[2];
		
		int x = press(s);
		if (x == len(res) + 1) res += ls[0];
		else if (x == len(res) + 2) res += ls[1];
		else res += ls[2];
	}
	
	if (press(res + ls[0]) == n) res += ls[0];
	else if (press(res + ls[1]) == n) res += ls[1];
	else res += ls[2];
	return res;
}

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