Submission #896118

#	Time	Username	Problem	Language	Result	Execution time	Memory
896118		wood	Combo (IOI18_combo)	C++17	Compilation error	0 ms	0 KiB

combo

#include <bits/stdc++.h>  
using namespace std;
 
typedef long long ll;
typedef pair<int,int> p32;
typedef pair<ll,ll> p64;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)

int press(string p);

string guess_sequence(int n){
    char start;
    if(press("AB")){
        if(press("A"))
        start = 'A';
        else start = 'B';
    } 
    else{
        if(press("X"))
        start = 'X';
        else start = 'Y';
    }
    string p = "";
    p+=start;
    vector<char> ch = {'A','B','X','Y'};
    ch.erase(lower_bound(ch.begin(),ch.end(),start));
    for (size_t i = 0; i < n-2; i++)
    {
        int guess = press(p+ch[0]+ch[0]+p+ch[0]+ch[1]+p+ch[0]+ch[2]+p+ch[1]);
        if(guess==p.size()+2) p+=ch[0];
        else if(guess==p.size()+1) p+=ch[1];
        else p+=ch[2];
    }
    if(press(p+ch[0])==n) return p+ch[0]+'\n';
    else if(press(p+ch[1])==n) return p+ch[1]+'\n';
    else return p+ch[2]+'\n';
}
int main()
{
    fast_cin();
    #ifndef ONLINE_JUDGE
        #ifdef _WIN32
            freopen("input.in", "r", stdin);
            freopen("input.out", "w", stdout);
        #else
            freopen(".in", "r", stdin);
            freopen(".out", "w", stdout);
        #endif
    #endif
    int n;
    cin>>n;
    cout<<guess_sequence(n);
    return 0;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:31:26: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   31 |     for (size_t i = 0; i < n-2; i++)
      |                        ~~^~~~~
combo.cpp:34:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         if(guess==p.size()+2) p+=ch[0];
      |            ~~~~~^~~~~~~~~~~~
combo.cpp:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |         else if(guess==p.size()+1) p+=ch[1];
      |                 ~~~~~^~~~~~~~~~~~
combo.cpp: In function 'int main()':
combo.cpp:50:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |             freopen(".in", "r", stdin);
      |             ~~~~~~~^~~~~~~~~~~~~~~~~~~
combo.cpp:51:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |             freopen(".out", "w", stdout);
      |             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cckvYy65.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cchqvbT5.o:combo.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status