Submission #252564

#	Time	Username	Problem	Language	Result	Execution time	Memory
252564		ChrisT	Combo (IOI18_combo)	C++17	100 / 100	40 ms	672 KiB

combo

#include<bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence (int n) {
	string ret; char fi;
	if (press("XY")) {
		ret += (fi = press("X") ? 'X' : 'Y');
	} else {
		ret += (fi = press("A") ? 'A' : 'B');
	}
	char a = 'A' + (fi == 'A');
	char b = fi <= 'B' ? 'X' : 'B';
	char c = fi <= 'X' ? 'Y' : 'X';
	for (int i = 2; i < n; i++) {
		int go = press(ret + a + ret + b + a + ret + b + b + ret + b + c);
		if (go == i+1) ret += b;
		else if (go == i) ret += a;
		else ret += c;
	}
	if (ret.length() < n) {
		int go = press(ret + a + ret + b);
		if (go == n) {
			ret += press(ret + a) == n ? a : b;
		} else {
			ret += c;
		}
	}
	return ret;
} 

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:20:19: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   20 |  if (ret.length() < n) {
      |      ~~~~~~~~~~~~~^~~

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