In honor of Lothar Collatz
In 1937, a German mathematician named Lothar Collatz formulated an intriguing hypothesis (it still remains unproven) which can be described in the following way:
take any non-negative and non-zero integer number and name it c0;
if it's even, evaluate a new c0 as c0 ÷ 2;
otherwise, if it's odd, evaluate a new c0 as 3 × c0 + 1;
if c0 ≠ 1, skip to point 2.
The hypothesis says that regardless of the initial value of c0, it will always go to 1.
My code:
def collatz(c0): count = 0 while c0 != 1: count += 1 if c0 % 2 == 0: c0 = c0 // 2 elif c0 % 2 == 1: c0 = c0*3 + 1 print(c0) else: print("steps = ", count) collatz(int(input('type any non-negative and non-zero integer number: ')))
It is important that the indentations in the code must be right!
Test Data
Sample input: 15 Expected output: 46 23 70 35 106 53 160 80 40 20 10 5 16 8 4 2 1 steps = 17
Sample input: 16 Expected output: 8 4 2 1 steps = 4
Sample input: 1023 Expected output: 3070 1535 4606 2303 6910 3455 10366 5183 15550 7775 23326 11663 34990 17495 52486 26243 78730 39365 118096 59048 29524 14762 7381 22144 11072 5536 2768 1384 692 346 173 520 260 130 65 196 98 49 148 74 37 112 56 28 14 7 22 11 34 17 52 26 13 40 20 10 5 16 8 4 2 1 steps = 62
Two related knowledge of python:
1. Count loops-https://www.tutorialspoint.com/python/python_while_loop.htm