/* * SOLVED * Problem: Find the largest palindrome made from the product of two 3-digit numbers. */ public static void ProblemAnswer() { /*Better than a brute force method*/ int largestPalindrome = 0; for (int x = 999; x >= 100; x--) { for (int y = 999; y >= x; y--) { int product = x * y; if (product <= largestPalindrome) { break; } if (EulerHelper.IsPalindrome(product)) { largestPalindrome = product; } } } Console.WriteLine("Euler Problem 4 Answer: " + largestPalindrome); Console.Write("Press ENTER to continue."); Console.ReadLine(); }
/* * SOLVED * Problem: What is the largest prime factor of the number 600851475143? */ public static void ProblemAnswer() { var bigNum = 600851475143; for (var i = 2; i *i < bigNum; i++) { if (bigNum % i == 0 && EulerHelper.IsPrime(i)) { bigNum /= i; } } Console.WriteLine("Euler Problem 3 Answer: " + bigNum); Console.Write("Press ENTER to continue."); Console.ReadLine(); }
/* SOLVED * * Problem: By considering the terms in * the Fibonacci sequence whose values do not exceed * four million, find the sum of the even-valued terms. */ public static int Fib(int n) { return(EulerHelper.FibNthValue(n)); }