Added comment to Fenwick Tree

pablomiralles22 · pablomiralles22 · commit 2db4c8db4fd2 · 2019-10-21T16:37:54.000+02:00
diff --git a/data_structures/fenwick_tree/fenwick_tree.py b/data_structures/fenwick_tree/fenwick_tree.py
@@ -7,6 +7,12 @@ def LSB(n):
 
 
 class FenwickTree:
+    '''
+    A Fenwick Tree allows you to sum a range of elements and update an element in an array in O(log(n)). A segment tree
+    can also achieve this, but it takes twice the memory, making it less memory efficient. On the other hand, a segment tree
+    can compute more functions in a range of elements, like the minimum or maximum.
+    '''
+
     def __init__(self, array):
         self.len = len(array)+1
         self.arr = [0] * self.len
