Submission #290575

#	Time	Username	Problem	Language	Result	Execution time	Memory
290575		gabrc52	Combo (IOI18_combo)	C++14	100 / 100	40 ms	768 KiB

combo

#include <iostream>
#include <string>
//#define DEBUG
#ifdef DEBUG
#define watch(x) cerr<<#x<<": "<<(x)<<endl
#else
#define watch(x)   
#endif
#include "combo.h"

using namespace std;

char getFirst() {
	if (press("AB") >= 1) {
		return press("A")==1 ? 'A' : 'B';
	} else {
		return press("X")==1 ? 'X' : 'Y';
	}
}

string valid = "ABXY";

string newValid(string s, char first) {
	string r;
	for (char c : s) {
		if (c != first) {
			r.push_back(c);
		}
	}
	return r;
}

int sz(string s) {
	return s.size();
}

string guess_sequence(int N) {
	string p,S;
	char first = getFirst();
	S.push_back(first);
	watch(first);
	if (N > 1) {
		valid = newValid(valid,first);
		watch(valid);
		for (int i=2; i<N; i++) {
			int r = press(S+valid[0] + S+valid[1]+valid[0] + S+valid[1]+valid[1] + S+valid[1]+valid[2]);
			if (r == sz(S)) {
				S.push_back(valid[2]);
			} else if (r == sz(S) + 1) {
				S.push_back(valid[0]);
			} else {
				S.push_back(valid[1]);
			}
			watch(S);
		}
		if (press(S+valid[0] + S+valid[1]) == sz(S)) {
			S.push_back(valid[2]);
		} else if (press(S+valid[0]) == sz(S)) {
			S.push_back(valid[1]);
		} else {
			S.push_back(valid[0]);
		}
		watch(S);
	}
	return S;
}

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