Ejercicio 3

exercises/ex03/ex03.py

@@ -0,0 +1,42 @@
+"""
+# collatz()
+
+Write a function named collatz() that has one parameter named number. If
+number is even, then collatz() should print number / 2 and return this value.
+If number is odd, then collatz() should print and return 3 * number + 1.
+
+Then write a program that lets the user type in an integer and that
+keeps calling collatz() on that number until the function returns the value 1.
+(Amazingly enough, this sequence actually works for any integer—sooner or
+later, using this sequence, you’ll arrive at 1! Even mathematicians aren’t sure
+why. Your program is exploring what’s called the Collatz sequence, sometimes
+called “the simplest impossible math problem.”)
+"""
+
+import time
+
+
+def collatz(number):
+    if number % 2 == 0:
+        res = int(number / 2)
+    else:
+        res = 3 * number + 1
+    print(res)
+    return res
+
+
+def cli():
+    print("Ingresa un número entero:", end=" ")
+    number = input()
+    try:
+        number = int(number)
+        wait = 0.1 / len(str(number))
+        while number != 1:
+            number = collatz(number)
+            time.sleep(wait)
+    except ValueError:
+        print(f"¡'{number}' no es un número entero!")
+        cli()
+
+
+cli()