Submission #750080

#	Time	Username	Problem	Language	Result	Execution time	Memory
750080		vjudge1	Combo (IOI18_combo)	C++14	100 / 100	29 ms	584 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;

string opt = "XYAB";
string guess_sequence(int n){
	// check first
	char first_char;
	if (press("AB")){
		if (press("A")){
			first_char = 'A';
		}else{
			first_char = 'B';
		}
	}else{
		if (press("X")){
			first_char = 'X';
		}else{
			first_char = 'Y';
		}
	}

	string pref; pref += first_char;

	vector<string> mp;
	// if A is first_char ->
	// 0 -> XX
	// 1 -> XY
	// 2 -> XB
	// 3 -> YX
	// ...
	// 8 -> BB
	if (first_char == 'X' || first_char == 'Y') opt = "ABXY";
	for (int i = 0; i < 4; i++){
		for (int j = 0; j < 4; j++){
			if (opt[i] == first_char || opt[j] == first_char) continue;
			mp.push_back(string{opt[i], opt[j]});
		}
	}

	for (int i = 1; i < n - 1; i++){
		string first_query = pref + mp[0] + pref + mp[1] + pref + mp[4];
		int res1 = press(first_query);
		if (res1 == 0 + pref.length()){
			pref += mp[6][0];
		}else{
			string second_query;
			if (res1 == 1 + pref.length()) second_query = pref + mp[3];
			else second_query = pref + mp[0];
			int res2 = press(second_query);
			if (res2 == 0 + pref.length()){
				pref += (res1 == 1 + pref.length() ? mp[2] : mp[4]);
			}else if (res2 == 1 + pref.length()){
				pref += (res1 == 1 + pref.length() ? mp[5] : mp[1]);
			}else{
				pref += (res1 == 1 + pref.length() ? mp[3] : mp[0]);
			}
			i++;
		}
	}
	if (pref.length() == n) return pref;
	char last_char;
	int k = 0;
	for (int i = 0; i < 4; i++){
		if (opt[i] == first_char) continue;
		k++;
		if (k == 2) last_char = opt[i];
		else if (press(pref + opt[i]) > pref.length()){
			last_char = opt[i];
			break;
		}
	}
	pref += last_char;

	return pref;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:44:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |   if (res1 == 0 + pref.length()){
      |       ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:48:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |    if (res1 == 1 + pref.length()) second_query = pref + mp[3];
      |        ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:51:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |    if (res2 == 0 + pref.length()){
      |        ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:52:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     pref += (res1 == 1 + pref.length() ? mp[2] : mp[4]);
      |              ~~~~~^~~~~~~~~~~~~~~~~~~~
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 (res2 == 1 + pref.length()){
      |              ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:54:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     pref += (res1 == 1 + pref.length() ? mp[5] : mp[1]);
      |              ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:56:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |     pref += (res1 == 1 + pref.length() ? mp[3] : mp[0]);
      |              ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:61:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   61 |  if (pref.length() == n) return pref;
      |      ~~~~~~~~~~~~~~^~~~
combo.cpp:68:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |   else if (press(pref + opt[i]) > pref.length()){
      |            ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~

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