Submission #1100383

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100383		akzytr	Combo (IOI18_combo)	C++17	97 / 100	29 ms	1956 KiB

combo

#include <bits/stdc++.h>
using namespace std;
template <typename T> using ve = vector<T>;
template <typename T, int sz> using ar = array<T, sz>;
typedef long long ll;
#define pb push_back
#define fi first
#define se second
#define endl '\n'

int press(string p);
string guess_sequence(int N) {
	string s = "";
	ve<char> lst;

	for(char j : {'A', 'B', 'X', 'Y'}) {
		lst.pb(j);
	}

	for(char j : lst) {
		int sc = press(s + j);
		if(sc == 1) {
			s += j;
			break;
		} else if(j == lst[lst.size() - 2]) {
			s += lst[lst.size() - 1];
			break;
		}
	}

	for(int i = 1; i < N - 1; i++) {
		ve<char> lst;

		for(char j : {'A', 'B', 'X', 'Y'}) {
			if(j == s[0]) {
				continue;
			}
			lst.pb(j);
		}

		string q = "";

		q += s + lst[0];
		q += s + lst[1] + lst[0];
		q += s + lst[1] + lst[1];
		q += s + lst[1] + lst[2];

		int score = press(q);
		if(score == s.size() + 1) {
			s += lst[0];
		} else if(score == s.size()) {
			s += lst[2];
		} else if(score == s.size() + 2) {
			s += lst[1];
		}
	}

	lst.clear();
	for(char j : {'A', 'B', 'X', 'Y'}) {
		if(j == s[0]) {
			continue;
		}
		lst.pb(j);
	}

	if(N > 1) {
		for(char j : lst) {
			int sc = press(s + j);
			if(sc == N) {
				s += j;
				break;
			} else if(j == lst[lst.size() - 2]) {
				s += lst[lst.size() - 1];
				break;
			}
		}
	}

	return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:49:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |   if(score == s.size() + 1) {
      |      ~~~~~~^~~~~~~~~~~~~~~
combo.cpp:51:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |   } else if(score == s.size()) {
      |             ~~~~~~^~~~~~~~~~~
combo.cpp:53:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |   } else if(score == s.size() + 2) {
      |             ~~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 92 / 95