Q3

using System; using System.Collections.Generic; using System.Text; using System.Collections; namespace EulerProject { class Program { static void question() { /* 600851475143의 가장 큰 소인수를 구하라 */ const double targetNumber = 600851475143; double tempFactor1 = targetNumber; double tempFactor2 = getPrimeFactors(tempFactor1); ArrayList al = new ArrayList(); while (true) { al.Add(tempFactor2); if (tempFactor2 != tempFactor1) { tempFactor1 /= tempFactor2; tempFactor2 = getPrimeFactors(tempFactor1); } else break; } al.Sort(); Console.WriteLine("Q3:{0}", al[al.Count-1]); } static void Main(string[] args) { question(); } static double getPrimeFactors(double targetNumber) { double pf = 1; while (true) { pf++; if (targetNumber % pf == 0) return pf; } } } }