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  1. #include<bits/stdc++.h>
  2. using namespace std;
  3. typedef long long ll;
  4. void File()
  5. {
  6.     freopen("in.txt","r",stdin);
  7.     freopen("out.txt","w",stdout);
  8. }
  9. string s,ans="";
  10. ll cnt = 0,I;
  11. void BT(int i);
  12. int main()
  13. {
  14.     ios_base::sync_with_stdio(false);
  15.     cin.tie(0);
  16.     cout.tie(0);
  17.     File();
  18.     int T;
  19.     cin>>T;
  20.     while(T--)
  21.     {
  22.         cin>>s>>I;
  23.         BT(0);
  24.         ans.clear();
  25.         cnt = 0;
  26.     }
  27.     return 0;
  28. }
  29. void BT(int i)
  30. {
  31.     if(cnt == I)return;
  32.     if(ans.size()==s.size())
  33.     {
  34.         cnt++;
  35.         if(cnt == I)cout<<ans<<endl;
  36.         return;
  37.     }
  38.     for(int j=0;j<=ans.size();++j)
  39.     {
  40.         string x="";
  41.         x+=s[i];
  42.         ans.insert(j,x);
  43.         BT(i+1);
  44.         ans.erase(j,1);
  45.         if(cnt == I)return;
  46.     }
  47. }
  48.  
Runtime error #stdin #stdout #stderr 0s 15240KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
stderr 
terminate called after throwing an instance of 'std::ios_base::failure[abi:cxx11]'
  what():  basic_filebuf::underflow error reading the file: iostream error
https://ideone.com/YKNCzG
language:
C++ (gcc 8.3)
created:
7 years ago
visibility:
public

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