Merge pull request kennyledet#355 from jcla1/master

jcla1 · jcla1 · commit 516c82248b28 · 2014-06-07T19:20:40.000+01:00
Added Ackermann function &amp; Catalan numbers in Go
diff --git a/Ackermann/Go/jcla1/ackermann.go b/Ackermann/Go/jcla1/ackermann.go
@@ -0,0 +1,11 @@
+package ackermann
+
+func Compute(m, n int) int {
+	if m == 0 {
+		return n + 1
+	} else if m > 0 && n == 0 {
+		return Compute(m-1, 1)
+	}
+
+	return Compute(m-1, Compute(m, n-1))
+}
diff --git a/Catalan_Numbers/Go/jcla1/catalan.go b/Catalan_Numbers/Go/jcla1/catalan.go
@@ -0,0 +1,33 @@
+package catalan
+
+func Direct(n int) int {
+	return fact(2*n) / (fact(n+1) * fact(n))
+}
+
+func Binomial(n int) int {
+	if n == 0 {
+		return 1
+	}
+
+	return binomialCoeff(2*n, n) - binomialCoeff(2*n, n-1)
+}
+
+func Sum(n int) (sum int) {
+	for i := 0; i <= n; i++ {
+		v := binomialCoeff(n, i)
+		sum += v * v
+	}
+	return
+}
+
+func binomialCoeff(n, k int) int {
+	return fact(n) / (fact(n-k) * fact(k))
+}
+
+func fact(n int) int {
+	if n <= 1 {
+		return 1
+	}
+
+	return n * fact(n-1)
+}
diff --git a/Catalan_Numbers/Python/jcla1/catalan.py b/Catalan_Numbers/Python/jcla1/catalan.py
@@ -5,9 +5,6 @@ def catalan_binomial(n):
     if n == 0: return 1
     return binomial_coefficient(2 * n, n) - binomial_coefficient(2 * n, n - 1)
 
-def catalan_fact(n):
-    return factorial(2 * n) / (factorial(n + 1) * factorial(n))
-
 def catalan_sum(n):
     return sum([binomial_coefficient(n, i) ** 2 for i in xrange(n + 1)]) / (n + 1)
 
@@ -20,6 +17,5 @@ def factorial(n):
 if __name__ == '__main__':
     # Make sure all implementations give the same results
     print(all([catalan_direct(n)
-            == catalan_binomial(n)
             == catalan_binomial(n)
             == catalan_sum(n) for n in xrange(100)]))
