Another update from ingydotnet^djgoku

Task/Permutations/Python/permutations-2.py

@@ -0,0 +1,26 @@
+def perm1(n):
+    a = list(range(n))
+    def sub(i):
+        if i == n - 1:
+            yield tuple(a)
+        else:
+            for k in range(i, n):
+                a[i], a[k] = a[k], a[i]
+                yield from sub(i + 1)
+                a[i], a[k] = a[k], a[i]
+    yield from sub(0)
+
+def perm2(n):
+    a = list(range(n))
+    def sub(i):
+        if i == n - 1:
+            yield tuple(a)
+        else:
+            for k in range(i, n):
+                a[i], a[k] = a[k], a[i]
+                yield from sub(i + 1)
+            x = a[i]
+            for k in range(i + 1, n):
+                a[k - 1] = a[k]
+            a[n - 1] = x
+    yield from sub(0)