Submission #605573

#	Time	Username	Problem	Language	Result	Execution time	Memory
605573		Clan328	Combo (IOI18_combo)	C++17	100 / 100	35 ms	588 KiB

combo

#include <bits/stdc++.h>

using namespace std;

#define pb push_back

int press(std::string p);

string guess_sequence(int N) {
	// Guess first letter
	string s = "";

	if (press("AB") > 0) {
		if (press("A") > 0) s += 'A';
		else s += 'B';
	} else {
		if (press("X") > 0) s += 'X';
		else s += 'Y';
	}

	vector<string> letters;
	if (s[0] != 'A') letters.pb("A");
	if (s[0] != 'B') letters.pb("B");
	if (s[0] != 'X') letters.pb("X");
	if (s[0] != 'Y') letters.pb("Y");
	letters.pb("");
	letters[3] += s[0];

	for (int i = 1; i < N-1; i++) {
		string q = s + letters[0]+letters[1] + s+ letters[0]+letters[2] + s+letters[0]+letters[0] + s +letters[1];
		int ans = press(q);
		if (ans == s.size()) s += letters[2];
		else if (ans == s.size()+1) s += letters[1];
		else s += letters[0];
	}

	if (s.size() < N) {
		if (press(s+letters[0]) > s.size()) s += letters[0];
		else if (press(s+letters[1]) > s.size()) s+= letters[1];
		else s+=letters[2];
	}

	return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:32:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |   if (ans == s.size()) s += letters[2];
      |       ~~~~^~~~~~~~~~~
combo.cpp:33:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |   else if (ans == s.size()+1) s += letters[1];
      |            ~~~~^~~~~~~~~~~~~
combo.cpp:37:15: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |  if (s.size() < N) {
      |      ~~~~~~~~~^~~
combo.cpp:38:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |   if (press(s+letters[0]) > s.size()) s += letters[0];
      |       ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
combo.cpp:39:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |   else if (press(s+letters[1]) > s.size()) s+= letters[1];
      |            ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~

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