Data commit

Task/Prime-decomposition/Groovy/prime-decomposition-1.groovy

@@ -0,0 +1,29 @@
+def factorize = { long target ->
+
+    if (target == 1) return [1L]
+
+    if (target < 4) return [1L, target]
+
+    def targetSqrt = Math.sqrt(target)
+    def lowfactors = (2L..targetSqrt).findAll { (target % it) == 0 }
+    if (lowfactors == []) return [1L, target]
+    def nhalf = lowfactors.size() - ((lowfactors[-1]**2 == target) ? 1 : 0)
+
+    [1] + lowfactors + (0..<nhalf).collect { target.intdiv(lowfactors[it]) }.reverse() + [target]
+}
+
+def decomposePrimes = { target ->
+    def factors = factorize(target) - [1]
+    def primeFactors = []
+    factors.eachWithIndex { f, i ->
+        if (i==0 || factors[0..<i].every {f % it != 0}) {
+            primeFactors << f
+            def pfPower = f*f
+            while (target % pfPower == 0) {
+                primeFactors << f
+                pfPower *= f
+            }
+        }
+    }
+    primeFactors
+}

Task/Prime-decomposition/Groovy/prime-decomposition-2.groovy

@@ -0,0 +1 @@
+((1..30) + [97*4, 1000, 1024, 333333]).each { println ([number:it, primes:decomposePrimes(it)]) }

Task/Prime-decomposition/Groovy/prime-decomposition-3.groovy

@@ -0,0 +1,2 @@
+def isPrime = {factorize(it).size() == 2}
+(1..60).step(2).findAll(isPrime).each { println ([number:"2**${it}-1", value:2**it-1, primes:decomposePrimes(2**it-1)]) }