From 7b624de8e3e3637a07364f992c1d7e4185e4a872 Mon Sep 17 00:00:00 2001
From: Charles <sircharlesaze@gmail.com>
Date: Sun, 11 Aug 2019 18:42:52 +0200
Subject: initial commit

---
 python/14-longest_collatz_sequence.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 python/14-longest_collatz_sequence.py

(limited to 'python/14-longest_collatz_sequence.py')

diff --git a/python/14-longest_collatz_sequence.py b/python/14-longest_collatz_sequence.py
new file mode 100644
index 0000000..e3c3caa
--- /dev/null
+++ b/python/14-longest_collatz_sequence.py
@@ -0,0 +1,16 @@
+from itertools import count
+
+
+def collatz_sequence_size(nb):
+    for i in count(1):
+        if nb == 1:
+            return i
+        nb = (nb / 2) if nb % 2 == 0 else (nb * 3 + 1)
+
+max_nb = (1, 0)
+for nb in range(1, 1_000_000):
+    col_seq_size = collatz_sequence_size(nb)
+    if col_seq_size > max_nb[1]:
+        max_nb = nb, col_seq_size
+
+print(max_nb)
-- 
cgit