Data commit

Task/Executable-library/Python/executable-library-1.py

@@ -0,0 +1,12 @@
+def hailstone(n):
+    seq = [n]
+    while n>1:
+        n = 3*n + 1 if n & 1 else n//2
+        seq.append(n)
+    return seq
+
+if __name__ == '__main__':
+    h = hailstone(27)
+    assert len(h)==112 and h[:4]==[27, 82, 41, 124] and h[-4:]==[8, 4, 2, 1]
+    print("Maximum length %i was found for hailstone(%i) for numbers <100,000" %
+          max((len(hailstone(i)), i) for i in range(1,100000)))