public static int twoNumConcat (int n1, int n2)
if (n2<10) return n1*10+n2;
return n2%10 + 10*twoNumConcat(n1,n2/10);
public static int SodSod (int n1, int n2)
if (n1<10 && n2<10) return n1*10+n2;
if (n1>=10 && n2<10) return n1*10+n2;
return n1%10*10 + n2%10+ 100*SodSod(n1/10,n2/10);
public static int fibonacciMember (int n)
return fibonacciMember(n-1) + fibonacciMember(n-2);
public static int arithmeticProgressionMember (int a1, int d, int n)
return d + arithmeticProgressionMember(a1,d,n-1);
public static int Sum (int n)
public static int Factorial (int n)
public static int Rev (int num)
public static int Rev (int n,int x)
return Rev(n / 10, x * 10 + n % 10);
public static bool IsAllEven (int[] ar)
private static bool IsAllEven (int[] ar, int i)
return ar[i]%2==0 && IsAllEven(ar,i+1);
public static bool IsAllEven1 (int[] ar)
return IsAllEven1(ar,ar.Length-1);
private static bool IsAllEven1 (int[] ar, int i)
return ar[i]%2==0 && IsAllEven1(ar,i-1);
public static int MaxAr (int[] ar)
private static int MaxAr (int[] ar, int i)
return Math.Max(ar[i],MaxAr(ar,i+1));
private static int MaxAr1 (int[] ar, int i)
int tmp = MaxAr1(ar,i+1);
public static int CountTav (char[] ar)
private static int CountTav (char[] ar, int i)
return 1 + CountTav(ar,i+1);
return 0 + CountTav(ar,i+1);
public static int NumOfDigits (int n)
return 1 + NumOfDigits(n/10);
public static int SumAr (int[] ar)
private static int SumAr (int [] ar, int i)
return ar[i] + SumAr(ar,i+1);
public static int SumAr1 (int [] ar, int i)
return ar[i] + SumAr1(ar,i-1);
public static int SumAr2 (int [] ar, int i)
return ar[i] + SumAr2(ar,i+1);
public static int SumAr3 (int [] ar, int i)
return ar[i] + SumAr3(ar,i+1);
public static int SumOfDigits (int n)
int ans = SumOfDigitsHelp(n);
public static int SumOfDigitsHelp (int n)
return (n%10) + SumOfDigitsHelp(n/10);
public static double FractionalPart (double num)
return FractionalPart(num-1);
public static int OddsProduct (int n)
return OddsProductHelp(n);
return OddsProductHelp(n-1);
public static int OddsProductHelp (int n)
return n*OddsProductHelp(n-2);
public static int Mult (int n, int m)
public static int Quotient (int n, int m)
return 1 + Quotient(n-m,m);
public static int Remainder (int n, int m)
public static int BigDig (int num)
return Math.Abs(num%10 - num/10);
int def = Math.Abs(n1-n2);
return Math.Max(def,BigDig(num/10));
public static void Main (string[] args)
Console.WriteLine(SodSod(135,246));
Console.WriteLine(SodSod(123,456));
Console.WriteLine(SodSod(78123,45));
Console.WriteLine(SodSod(12,7456));
Console.WriteLine(twoNumConcat(123,45));
Console.WriteLine(fibonacciMember(6));
Console.WriteLine(arithmeticProgressionMember(2,2,5));
Console.WriteLine(arithmeticProgressionMember(2,3,5));
Console.WriteLine(arithmeticProgressionMember(3,-2,4));
Console.WriteLine(arithmeticProgressionMember(3,-2,3));