Submission #272830

#	Time	Username	Problem	Language	Result	Execution time	Memory
272830		EJOI2019Andrew	Rack (eJOI19_rack)	C++14	40 / 100	1 ms	288 KiB

rack

#include<bits/stdc++.h>
using namespace std;
string ans;
map<int,int>freq;
long long int MOD=1000000007;
void rack(long long int k)
{
if(k==1&&freq[k]>1)
return;
if(k%2)
ans+='L';
else
ans+='R';
int fn(0);
if(k%2)
fn=1;
k/=2;
k+=fn;
++freq[k];
rack(k);
}
long long int solve(long long int n)
{
long long int l(1),r(pow(2,n));
for(int i=0; i<ans.length(); ++i)
{
long long int mid=(l+r)/2;
if(ans[i]=='R')
l=mid+1;
else
r=mid-1;
l%=MOD;
r%=MOD;
}
return l;
}
int main()
{
long long int n,k;
cin>>n>>k;
rack(k);
cout<<solve(n);
return 0;
}

Compilation message (stderr)

rack.cpp: In function 'long long int solve(long long int)':
rack.cpp:25:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 | for(int i=0; i<ans.length(); ++i)
      |              ~^~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 60