Submission #703149

#	Time	Username	Problem	Language	Result	Execution time	Memory
703149		PenguinsAreCute	Combo (IOI18_combo)	C++17	100 / 100	33 ms	648 KiB

combo

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

string guess_sequence(int N) {
	string p = ""; char c[4]; c[0] = 'A'; c[1] = 'B'; c[2] = 'X'; c[3] = 'Y';
	if(press("AB") == 0) {
		if(press("X") == 0) p = "Y";
		else {
			p = "X"; c[2] = 'Y';
		}
	} else {
		if(press("A") == 0) {
			p = "B"; c[1] = 'Y';
		} else {
			p = "A"; c[0] = 'Y';
		}
	}
	srand(4206969420);
	for(int i = 1; i < N - 1; i++) {
		string s = p + c[2] + c[0] + p + c[2] + c[1] + p + c[2] + c[2] + p + c[1];
		p += c[press(s) - i];
	}
	for(int i = max(N - 1, 1); i < N; i++) {
		for(int j = 1; j < 3; j++) {
			int sw = rand() % (j + 1);
			if(sw != j) swap(c[sw], c[j]);
		}
		for(int j = 0; j < 3; j++) {
			if(j == 0) p += c[j];
			else p[i] = c[j];
			if(j == 2 || press(p) == i + 1) break;
		}
	}
	return p;
}

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