add recursive soln.

2020-06-03 15:28:01 +02:00
parent d8da439590
commit 345d09b69e
4 changed files with 28 additions and 0 deletions
--- a/03_recursion/python/05_binary_search_recursive.py
+++ b/03_recursion/python/05_binary_search_recursive.py
@@ -0,0 +1,15 @@
+def binary_search(arr, target):
+    if not arr:
+        return -1        
+    if len(arr) == 1 and arr[0] == target:
+        return arr[0]
+    if len(arr) == 1 and arr[0] != target:
+        return -1
+    low = 0         
+    high = len(arr) - 1    
+    mid = (low + high) // 2
+
+    if arr[mid] > target:
+        return binary_search(arr[:mid], target)
+    else:
+        return binary_search(arr[mid+1:], target)