Submission #536410

#	Time	Username	Problem	Language	Result	Execution time	Memory
536410		fuad27	Combo (IOI18_combo)	C++17	100 / 100	34 ms	596 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
char keys[] = {'A','B','X','Y'};
string B = "", X ="", Y ="";
vector<char> keys2;
char next_char(string s) {
	B = "", X ="", Y ="";
	B.push_back(keys2[0]);
	X.push_back(keys2[1]);
	Y.push_back(keys2[2]);
	string ask = s+B + s + X + B + s + X + X + s + X + Y;
	int val = press(ask) - s.size();
	if(val == 1)return B[0];
	else if(val == 2)return X[0];
	return Y[0];
}
string guess_sequence(int n) {
	string p = "";
	if(press("AB")) {
		if(press("A"))p = "A";
		else p = "B";
	}
	else {
		if(press("X"))p = "X";
		else p = "Y";
	}
	if(n == 1)return p;
	char start = p[0];
	for(int i = 0;i<4;i++) {
		if(keys[i] == start)continue;
		keys2.push_back(keys[i]);
	}
	for(int j = 1;j<n-1;j++) {
		char c = next_char(p);
		p.push_back(c);
	}
	for(int i = 0;i<2;i++) {
		p.push_back(keys2[i]);
		if(press(p) == n) {
			break;
		}
		p.pop_back();
	}
	if((int)p.size()!=n) {
		p.push_back(keys2[2]);
	}
	return p;
}

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