Data commit

Task/Permutations/Wren/permutations-1.wren

@@ -0,0 +1,19 @@
+var permute // recursive
+permute = Fn.new { |input|
+    if (input.count == 1) return [input]
+    var perms = []
+    var toInsert = input[0]
+    for (perm in permute.call(input[1..-1])) {
+        for (i in 0..perm.count) {
+            var newPerm = perm.toList
+            newPerm.insert(i, toInsert)
+            perms.add(newPerm)
+        }
+    }
+    return perms
+}
+
+var input = [1, 2, 3]
+var perms = permute.call(input)
+System.print("There are %(perms.count) permutations of %(input), namely:\n")
+perms.each { |perm| System.print(perm) }

Task/Permutations/Wren/permutations-2.wren

@@ -0,0 +1,27 @@
+import "/math" for Int
+
+var input = [1, 2, 3]
+var perms = [input]
+var a = input.toList
+var n = a.count - 1
+for (c in 1...Int.factorial(n+1)) {
+    var i = n - 1
+    var j = n
+    while (a[i] > a[i+1]) i = i - 1
+    while (a[j] < a[i])   j = j - 1
+    var t = a[i]
+    a[i] = a[j]
+    a[j] = t
+    j = n
+    i = i + 1
+    while (i < j) {
+        t = a[i]
+        a[i] = a[j]
+        a[j] = t
+        i = i + 1
+        j = j - 1
+    }
+    perms.add(a.toList)
+}
+System.print("There are %(perms.count) permutations of %(input), namely:\n")
+perms.each { |perm| System.print(perm) }

Task/Permutations/Wren/permutations-3.wren

@@ -0,0 +1,6 @@
+import "./perm" for Perm
+
+var a = [1, 2, 3]
+System.print(Perm.list(a))    // not lexicographic
+System.print()
+System.print(Perm.listLex(a)) // lexicographic