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.
class Program
{
static void Main(string[] args)
{
/*
* 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.
*/
Console.WriteLine(CheckPalindromicNumber(123));
Console.WriteLine(CheckPalindromicNumber(121));
Console.WriteLine(CheckPalindromicNumber(1221));
Console.WriteLine(CheckPalindromicNumber(12321));
int k = 1;
for (int i = 999; i >= 0; i--)
{
for (int j = 999; j >= 0; j--)
{
int n = i*j;
if (n > k && CheckPalindromicNumber(n))
{
k = n;
}
}
}
Console.WriteLine(k);
}
private static bool CheckPalindromicNumber(int n)
{
string nString = n.ToString();
for (int a = 0, b = nString.Length - 1; a < b; a++, b--)
{
if (nString[a] != nString[b]) return false;
}
return true;
}
}