MNada MNada - 1 month ago 6
C++ Question

Debug Error -Abort() Has Been Called

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 4 and 7. For example, numbers 47, 7744, 474477 are super lucky and 4, 744, 467 are not.

Here's my code

#include<iostream>
#include<string>
using namespace std;

void superLucky(int n,string s, int count4, int count7)
{
if (s.size() > 10)
return;
if (( stoi(s) >= n ) && (count4 == count7) && (count4+count7)!=0)
{
cout << s << endl;
return;
}

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

int main()
{
int n;
cin >> n;
superLucky(n, "", 0, 0);
return 0;
}


Once I input some integer I get debug error R6010 - abort() has been called. What this means ? and how can I fix this ?

Answer

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);
}