京东2018秋招c++岗 神奇数

bool isfind(vector<int>& nums, int sum, int cur, int begin)
{
    if( begin == nums.size() ) return false;
    if( cur == sum / 2 ) return true;
    bool res1 = isfind( nums, sum, cur+nums[begin], begin+1 );
    if( res1 ) return true;
    bool res2 = isfind( nums, sum, cur, begin+1 );
    if( res2 ) return true;
    return res1 || res2;
}

bool fenjie(long long n)
{
  vector<int> dig;
  int sum = 0;
  if(n==0)
  {
    dig.push_back(0);
    return false;
  }
  int t =0;
   while(n>0)
   {
     t = n%10;
     n/=10;
dig.push_back(t);
sum+=t;
  }
  sort(dig.begin(),dig.end());
  if(sum&1)return false;
  return isfind(dig,sum,0,0);
}
void core()
{
  int n,m,ret =0;
  cin>>n>>m;
  for( int i = n; i <= m; i++ )
    {
       if (fenjie(i))ret++;
    }
  cout<<ret<<endl;
}
int main()
{ 
   core();  
}