public class Summe { static public long sumIt(long n) { long summe = 0; for (long i = 1; i <= n; i++) summe += i; return summe; } static public long sumRec(long n) { if (n == 1) return 1; return n + sumRec(n-1); } static public long sumRecHelper(final long n, long i) { if (i > n) return 0; return i + sumRecHelper(n, i+1); } }