Implement an in-place shuffling algorithm

I believe this may be the Fisher-Yates shuffle, but I'm not sure.

2 files changed, 22 insertions, 2 deletions

diff --git a/scratch/deepmind/part_two/shuffle.py b/scratch/deepmind/part_two/shuffle.py
new file mode 100644
index 000000000000..fdc5a8bd80ab
--- /dev/null
+++ b/scratch/deepmind/part_two/shuffle.py
@@ -0,0 +1,20 @@
+import random
+
+
+def get_random(floor, ceiling):
+    return random.randrange(floor, ceiling + 1)
+
+
+def shuffle(xs):
+    n = len(xs)
+    for i in range(n - 1):
+        j = get_random(i + 1, n - 1)
+        xs[i], xs[j] = xs[j], xs[i]
+
+
+sample_list = [1, 2, 3, 4, 5]
+print('Sample list:', sample_list)
+
+print('Shuffling sample list...')
+shuffle(sample_list)
+print(sample_list)
diff --git a/scratch/deepmind/part_two/todo.org b/scratch/deepmind/part_two/todo.org
index 078613611618..228dd08ef3f6 100644
--- a/scratch/deepmind/part_two/todo.org
+++ b/scratch/deepmind/part_two/todo.org
@@ -13,8 +13,8 @@
 ** DONE Apple Stocks
 ** DONE Highest Product of 3
 ** DONE Product of All Other Numbers
-** TODO Cafe Order Checker
-** TODO In-Place Shuffle
+** DONE Cafe Order Checker
+** DONE In-Place Shuffle
 * Sorting, searching, and logarithms
 ** TODO Find Rotation Point
 ** TODO Find Repeat, Space Edition