From 7ffedd972ab11ae466a9404b062bcaa5caf40558 Mon Sep 17 00:00:00 2001
From: Michael Soukup <michael@soukup.io>
Date: Sat, 8 Nov 2025 18:09:40 +0100
Subject: [PATCH] Secret santa script

---
 README.md       | 12 ++++++++++++
 secret-santa.py | 19 +++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 README.md
 create mode 100755 secret-santa.py

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..152b4ea
--- /dev/null
+++ b/README.md
@@ -0,0 +1,12 @@
+# Secret Santa
+
+Example usage:
+
+```
+$ ./secret-santa.py Elsa Anna Kristoffer Svein Olaf
+Svein -> Elsa
+Elsa -> Olaf
+Olaf -> Kristoffer
+Kristoffer -> Anna
+Anna -> Svein
+```
diff --git a/secret-santa.py b/secret-santa.py
new file mode 100755
index 0000000..8c9df41
--- /dev/null
+++ b/secret-santa.py
@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+import sys
+import random
+
+rng = random.SystemRandom()
+
+def secret_santa(names):
+    """Draw pairings for secret santa.
+
+    We recognize the problem as a random Hamiltonian cycle
+    on the complete graph formed by the set of names.
+    """
+    g = list(names)
+    rng.shuffle(g)
+    return list(zip(g, g[1:] + g[:1]))
+
+if __name__ == '__main__':
+    for pair in secret_santa(sys.argv[1:]):
+        print("%s -> %s" % pair)