My solve AC with 0.0001 and 528 kb

#include <iostream.h>
#include <math.h>
#include <stdlib.h>
int fcmp (const void* a, const void* b)
{ return *(int*)a - *(int*)b;
}
int main()
{ int a[10], div[100000], count=0, i;
  for (i=0; i<10; i++)

    cin>>a[i];
  for (i=0; i<10; i++)
    { while (a[i]%2==0)
        { div[count++] = 2;
          a[i] /= 2;
        }
      int j=3;
      while (j <= sqrt( (double)a[i] ) + 1)
        { if (a[i]%j==0)
            { div[count++]=j;
              a[i] /= j;
            }
          else j += 2;
        }
      if (a[i]>1) div[count++]=a[i];
    }
  qsort(div, count, sizeof(int), fcmp);
  int proiz=1, temp=1;
  for (i=0; i<count; i++)
    { if (div[i]==div[i+1]) temp++;
      else
        { proiz *= (temp+1)%10; temp=1;}
    }
  cout<<proiz%10;
        return 0;
}