【Project Euler】4 第四题

//A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.
//Find the largest palindrome made from the product of two 3-digit numbers.
      

  static void Main(string[] args)
        {
            int sum = 0;
            for (int i = 10; i < 1000; i++)
            {
                for (int j = 10; j < 1000; j++)
                {
                    sum = i * j;
                    if (sum / 100000 < 10)
                    {
                        int a = sum / 100000;
                        int b = (sum - a * 100000) / 10000;
                        int c = (sum - a * 100000 - b * 10000) / 1000;
                        int d = (sum - a * 100000 - b * 10000 - c * 1000) / 100;
                        int e = (sum - a * 100000 - b * 10000 - c * 1000 - d * 100) / 10;
                        int f = sum - a * 100000 - b * 10000 - c * 1000 - d * 100 - e * 10;
                        if (a == f && b == e && c == d)
                        {
                            if (sum > 900000)
                            {
                                Console.WriteLine(sum);
                            }
                        }
                    }
                }
            }
        }