all tasks

Task/Sorting-algorithms-Permutation-sort/Groovy/sorting-algorithms-permutation-sort-1.groovy

@@ -0,0 +1,22 @@
+def factorial = { (it > 1) ? (2..it).inject(1) { i, j -> i*j } : 1 }
+
+def makePermutation;
+makePermutation = { list, i ->
+    def n = list.size()
+    if (n < 2) return list
+    def fact = factorial(n-1)
+    assert i < fact*n
+
+    def index = i.intdiv(fact)
+    [list[index]] + makePermutation(list[0..<index] + list[(index+1)..<n], i % fact)
+}
+
+def sorted = { a -> (1..<(a.size())).every { a[it-1] <= a[it] } }
+
+def permutationSort = { a ->
+    def n = a.size()
+    def fact = factorial(n)
+    def permuteA = makePermutation.curry(a)
+    def pIndex = (0..<fact).find { print "."; sorted(permuteA(it)) }
+    permuteA(pIndex)
+}

Task/Sorting-algorithms-Permutation-sort/Groovy/sorting-algorithms-permutation-sort-2.groovy

@@ -0,0 +1,8 @@
+println permutationSort([7,0,12,-45,-1])
+println ()
+println permutationSort([10, 10.0, 10.00, 1])
+println permutationSort([10, 10.00, 10.0, 1])
+println permutationSort([10.0, 10, 10.00, 1])
+println permutationSort([10.0, 10.00, 10, 1])
+println permutationSort([10.00, 10, 10.0, 1])
+println permutationSort([10.00, 10.0, 10, 1])