github.com/sadikkuzu

code/sadikkuzu.py

@@ -0,0 +1,23 @@
+## https://gist.github.com/sadikkuzu/af6a69d73f463b1b6b30aec15935dbc9
+# https://www.wikiwand.com/en/Happy_number
+# http://mathworld.wolfram.com/HappyNumber.html
+
+
+def square(x):
+    return int(x) * int(x)
+
+
+def happy(number):
+    return sum(map(square, list(str(number))))
+
+
+def is_happy(number):
+    seen_numbers = set()
+    while number > 1 and (number not in seen_numbers):
+        seen_numbers.add(number)
+        number = happy(number)
+    return number == 1
+
+
+def is_happy2(n): # recursive
+    return (n == 1 or n > 4 and is_happy2(happy(n)))