Submission #897363

#	Time	Username	Problem	Language	Result	Execution time	Memory
897363		honanhphong	Combo (IOI18_combo)	C++14	5 / 100	1 ms	352 KiB

combo

#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define faster ios_base::sync_with_stdio(0); cin.tie(0);
using namespace std;
using lli = long long;
using ld = long double;
using pii = pair <int, int>;
mt19937_64 Rand(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 1e6 + 1000;
const int mod = 1e9 + 7;
int press(string p);



string guess_sequence(int N)
{
    string s = "";
    string p = "ABXY";
    char start;
    char cs[maxn];
    if(press("A")) s = "A";
    else if(press("B")) s = "B";
    else if(press("X")) s = "X";
    else s = "Y";
    if (s[0] == 'A')
    {
        cs[0] = 'B'; cs[1] = 'X'; cs[2] = 'Y';
    } else if (s[0] == 'B')
    {
        cs[0] = 'A'; cs[1] = 'X'; cs[2] = 'Y';
    } else if (s[0] == 'X')
    {
        cs[0] = 'A'; cs[1] = 'B'; cs[2] = 'Y';
    } else if (s[0] == 'Y')
    {
        cs[0] = 'A'; cs[1] = 'B'; cs[2] = 'X';
    }
    for (lli i = 0; i < N - 2; i ++)
    {
        lli guess = press(s + cs[0] + cs[0] + s + cs[0] + cs[1] + s + cs[0] + cs[2] + s + cs[1]);
        if (guess == s.size() + 2) s += cs[0];
        else if (guess == s.size() + 1) s += cs[1];
        else s += cs[2];
    }
    if (press(s + cs[0]) == N) return s + cs[0];
    else if (press(s + cs[1]) == N) return s + cs[1];
    else if (press(s + cs[2]) == N) return s + cs[2];
    return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:43:19: warning: comparison of integer expressions of different signedness: 'lli' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |         if (guess == s.size() + 2) s += cs[0];
      |             ~~~~~~^~~~~~~~~~~~~~~
combo.cpp:44:24: warning: comparison of integer expressions of different signedness: 'lli' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |         else if (guess == s.size() + 1) s += cs[1];
      |                  ~~~~~~^~~~~~~~~~~~~~~
combo.cpp:21:10: warning: unused variable 'start' [-Wunused-variable]
   21 |     char start;
      |          ^~~~~
combo.cpp:47:23: warning: 'cs[0]' may be used uninitialized in this function [-Wmaybe-uninitialized]
   47 |     if (press(s + cs[0]) == N) return s + cs[0];
      |                       ^
combo.cpp:49:28: warning: 'cs[2]' may be used uninitialized in this function [-Wmaybe-uninitialized]
   49 |     else if (press(s + cs[2]) == N) return s + cs[2];
      |                            ^
combo.cpp:48:28: warning: 'cs[1]' may be used uninitialized in this function [-Wmaybe-uninitialized]
   48 |     else if (press(s + cs[1]) == N) return s + cs[1];
      |                            ^

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95