Merge pull request #1438 from DontEatThemCookies/master

Collatz Conjecture Program

Author: geekcomputers

Collatz-Conjecture.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+
+# Recommended: Python 3.6+
+
+"""
+Collatz Conjecture - Python
+
+The Collatz conjecture, also known as the
+3x + 1 problem, is a mathematical conjecture
+concerning a certain sequence. This sequence
+operates on any input number in such a way
+hat the output will always reach 1.
+
+The Collatz conjecture is most famous for
+harboring one of the unsolved problems in
+mathematics: does the Collatz sequence really
+reach 1 for all positive integers?
+
+This program takes any input integer
+and performs a Collatz sequence on them.
+The expected behavior is that any number
+inputted will always reach a 4-2-1 loop.
+
+Do note that Python is limited in terms of
+number size, so any enormous numbers may be
+interpreted as infinity, and therefore
+incalculable, by Python. This limitation
+was only observed in CPython, so other
+implementations may or may not differ.
+
+11/24/2021
+David Costell (DontEatThemCookies on GitHub)
+"""
+
+import math
+
+print("Collatz Conjecture")
+number = input('Enter a number to calculate: ')
+try:
+    number = float(number)
+except:
+    print('Error: Could not convert to integer.')
+    print('Only integers/floats can be entered as input.')
+    input()
+    exit()
+
+# Checks to see if input is valid
+if number == 0:
+    input('Error: Zero is not calculable. ')
+    exit()
+if number < 0:
+    input('Error: Negative numbers are not calculable. ')
+    exit()
+if number == math.inf:
+    input('Error: Infinity is not calculable.')
+    exit()
+
+print('Number is', number)
+input('Press ENTER to begin.')
+print('BEGIN COLLATZ SEQUENCE')
+
+def modulo():
+    global number
+    modulo = number % 2 # Modulo the number by 2
+    if modulo == 0: # If the result is 0,
+        number = number / 2 # divide it by 2
+    else: # Otherwise,
+        number = number * 3 + 1 # multiply by 3 and add 1
+        
+def final():
+    print('END COLLATZ SEQUENCE')
+    print('Sequence has reached a 4-2-1 loop.')
+    input()
+    exit()
+    
+while True:
+    # Execute the sequence
+    modulo()
+    print(number)
+    if number == 1.0:
+        break
+
+final()