/// <summary>
/// http://projecteuler.net/problem=4
/// A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 x 99.
/// Find the largest palindrome made from the product of two 3-digit numbers.
/// </summary>
/// <param name="args"></param>
static void Main(string[] args)
{
Console.WriteLine("Project Euler\n\nProblem 4");
_4 main = new _4();
// Console.WriteLine("101 is " + (main.isPalindrome(101) ? "" : "not ") + "a palindrome."); //Test
int digit = 3;
int result = main.loop(main, digit);
if (result == 0)
Environment.Exit(-1); // Should not reach here.
Console.WriteLine("The largest palindrome made of two " + digit + " digit numbers is " + result);
Console.ReadKey();
}
public int loop(_4 main, int digits)
{
double start = 0;
for (int i = digits-1; i >= 0; i--)
{
start += Math.Pow(10, i) * 9;
}
int value1, value2;
for (value1 = (int)start; value1 > 900; value1--)
{
for (value2 = (int)start; value2 > 900; value2--)
{
if (main.isPalindrome(value1 * value2))
{
return value1 * value2;
}
}
}
return 0;
}