Submission #115387

#	Time	Username	Problem	Language	Result	Execution time	Memory
115387		kitoha	Combo (IOI18_combo)	C++14	97 / 100	51 ms	536 KiB

combo

#include "combo.h"
#include<bits/stdc++.h>

using namespace std;

char key[] = { 'A','B','X','Y' };

string guess_sequence(int N) {
	string s = "";
	char element[3];
	int pos = 0;
	int idx = 0;
	if (press("AB") >= 1) {
		if (press("A") >= 1) {
			s = "A";
			idx = 0;
		}
		else {
			s = "B";
			idx = 1;
		}
	}
	else {
		if (press("XY") >= 1) {
			if (press("X") >= 1) {
				s = "X"; 
				idx = 2;
			}
			else {
				s = "Y";
				idx = 3;
			}
		}
	}

	for (int i = 0; i <= 3; i++) {
		if (idx == i) continue;
		element[pos++] = key[i];
	}

	while((int)s.size()<=N-2) {
		string p = s + element[0] + element[0] + s + element[0] + element[1] + s + element[0] + element[2] + s + element[1];
		int cnt = press(p);
		if (cnt == (int)s.size() + 2) s = s + element[0];
		else if (cnt == (int)s.size() + 1) s = s + element[1];
		else s = s + element[2];
	}

	while ((int)s.size() != N) {
		if (press(s + element[0]) == (int)s.size() + 1) s = s + element[0];
		else if (press(s + element[1]) == (int)s.size() + 1) s = s + element[1];
		else s = s + element[2];
	}


	return s;
}

• Subtask 1: 5 / 5
• Subtask 2: 92 / 95