using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace SoloLearn { class Program { // finds all defecient numbers in a given range static List FindDefecientNumbers(int min, int max) { List defecientNumbers = new List(); for(int i = min; i<=max; i++) { if(IsDefecient(i)) { defecientNumbers.Add(i); } } return defecientNumbers; } static bool IsDefecient (int num) { // obtaining factors List factors = ObtainFactors(num); // calculating factors sum int factorsSum = SumFactors(factors); // checking if number is defecient bool isDefecient = num*2>factorsSum?true:false; return isDefecient; } static int SumFactors (List factors) { int sum = 0; foreach(int num in factors) { sum+=num; } return sum; } static List ObtainFactors(int num) { List factors = new List(); for(int i = 1; i <=num; i++) { if(num%i == 0) { factors.Add(i); } } return factors; } static void Main(string[] args) { List defecientNumbers = FindDefecientNumbers( 2,15); foreach (int num in defecientNumbers) { Console.Write(num+" "); } } } }

defecient Numbers