Submission #1303879

#	Time	Username	Problem	Language	Result	Execution time	Memory
1303879		Cr45hor	Combo (IOI18_combo)	C++17	100 / 100	8 ms	468 KiB

combo

#include "combo.h"

std::string guess_sequence(int N) {
    int id_first_char;
    char ch[] = {'A', 'B', 'X', 'Y'};
    std::string s = "";
    if (press("AB") > 0) {
        id_first_char = (press("A") == 0);
    }
    else {
        id_first_char = 2 + (press("X") == 0);
    }
    s += ch[id_first_char];
	if (N == 1) return s;
	std::swap(ch[id_first_char], ch[3]);

    for (int i = 1; i < N - 1; i++) {
		int x = press(s + ch[0] + ch[0] + s + ch[0] + ch[1] + s + ch[0] + ch[2] + s + ch[1]);
		if (x == i + 2) s+=ch[0];
		else if (x == i + 1) s+=ch[1];
		else s += ch[2];
	}
	if (press(s + ch[0]) == N) {
		s += ch[0];
	} else if (press(s + ch[1]) == N) {
        s += ch[1];
    } else {
        s += ch[2];
    }
	return s;
}

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