Submission #1147438

#	Time	Username	Problem	Language	Result	Execution time	Memory
1147438		weakweakweak	Combo (IOI18_combo)	C++20	100 / 100	7 ms	508 KiB

combo

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


std::string guess_sequence(int N) {
	char ez[4] = {'A', 'B', 'X', 'Y'};
	vector<char> v;
	char st, ed;
	string now;

	if (press("AB") >= 1) {
		if (press("A") == 1) st = 'A';
		else st = 'B';
	}
	else {
		if (press("X") == 1) st = 'X';
		else st = 'Y';
	}
	now += st;

	v.clear();
	for (int i = 0; i < 4; i++) if (ez[i] != st) v.push_back(ez[i]);
	for (int i = 1; i < N-1; i++) {
		string s;
		for (char c : v) {
			s += now + string(1,v[0]) + string(1,c);
		}
		s += now + string(1,v[1]);
		int z = press(s);
		if (z == i+2) now.push_back(v[0]);
		else if (z == i+1) now.push_back(v[1]);
		else now.push_back(v[2]);
	}

	if (N > 1) {
		if (press(now+string(1,v[0])) == N) now.push_back(v[0]);
		else if (press(now+string(1,v[1])) == N) now.push_back(v[1]);
		else now.push_back(v[2]);
	}

	return now;
}

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