# C#: Project Euler Solution to Problem 32

http://projecteuler.net/problem=32

We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once; for example, the 5-digit number, 15234, is 1 through 5 pandigital.

The product 7254 is unusual, as the identity, 39 x 186 = 7254, containing multiplicand, multiplier, and product is 1 through 9 pandigital.

Find the sum of all products whose multiplicand/multiplier/product identity can be written as a 1 through 9 pandigital.

```public static LinkedList<string> onetonine = new LinkedList<string>(); static void Main(string[] args) { LinkedList<int> distinct_product = new LinkedList<int>(); int product = 0; for (int a = 1; a < 2000; a++) { for (int b = 1; b < 2000; b++) { product = a * b;   if (isDigits(a + "" + b + "" + product)) { if (!distinct_product.Contains(product) ) distinct_product.AddLast(product); } } } int sum = 0; foreach (int prod in distinct_product) sum += prod; Console.WriteLine("sum : "+sum); }   public static bool isDigits(string s) { onetonine.Clear(); onetonine.AddLast("1"); onetonine.AddLast("2"); onetonine.AddLast("3"); onetonine.AddLast("4"); onetonine.AddLast("5"); onetonine.AddLast("6"); onetonine.AddLast("7"); onetonine.AddLast("8"); onetonine.AddLast("9"); if (s.Length != 9) return false; for (int i = 0; i < s.Length; i++) { if (onetonine.Contains("" + s[i])) onetonine.Remove("" + s[i]); else return false; } return true; }```