Debug Error -Abort() Has Been Called

Question

I\'m trying to enter a number,n and get the least super lucky number that is more than or equal to n. Super lucky: it\'s decimal representation contains equal amount of digits

Answer 1

There are couple of issues:

1. When you call superLucky from main, s is empty. stoi(s) throws an exception when s is empty.

2. The check s.size() > 10 is not robust. It is platform dependent. You can use a try/catch block to deal with it instead of hard coding a size.

Here's a more robust version of the function.

void superLucky(int n,string s, int count4, int count7)
{
   int d = 0;
   if ( s.size() > 0 )
   {
      try
      {
         d = stoi(s);
      }
      catch (...)
      {
         return;
      }

      if (( d >= n ) && (count4 == count7) && (count4+count7)!=0)
      {
         cout << s << endl;
         return;
      }
   }

   superLucky(n, s + '7',count4,count7+1);
   superLucky(n, s + '4', count4+1, count7);
}