From 7b3d385ad62a74b7e984c9b5424006566e4f848d Mon Sep 17 00:00:00 2001
From: praisearts <34782930+praisearts@users.noreply.github.com>
Date: Thu, 24 Oct 2019 09:31:58 +0100
Subject: [PATCH] create simple binary search (#1430)

* create simnple binary search

#A binary search implementation to test if a number is in a list of elements

* Add .py, format with psf/black, and add doctests
---
 searches/simple-binary-search.py | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 searches/simple-binary-search.py

diff --git a/searches/simple-binary-search.py b/searches/simple-binary-search.py
new file mode 100644
index 000000000..80e43ea34
--- /dev/null
+++ b/searches/simple-binary-search.py
@@ -0,0 +1,26 @@
+# A binary search implementation to test if a number is in a list of elements
+
+
+def binary_search(a_list, item):
+    """
+    >>> test_list = [0, 1, 2, 8, 13, 17, 19, 32, 42]
+    >>> print(binary_search(test_list, 3))
+    False
+    >>> print(binary_search(test_list, 13))
+    True
+    """
+    if len(a_list) == 0:
+        return False
+    midpoint = len(a_list) // 2
+    if a_list[midpoint] == item:
+        return True
+    if item < a_list[midpoint]:
+        return binary_search(a_list[:midpoint], item)
+    else:
+        return binary_search(a_list[midpoint + 1 :], item)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()