Exercises, typo

Author: lee-naish

src/algorithms/explanations/msort_arr_bup.md

@@ -35,5 +35,5 @@ fit into main memories. Historically, when data was primarily stored on
 magnetic tape, versions of bottom up merge sort were absolutely essential.
 There are recursive "top down" versions of merge sort, shown elsewhere.
 There is also a "natural" merge sort which utilises already sorted runs,
-also shown elsewhere
+also shown elsewhere.
 

src/algorithms/extra-info/AVLInfo.md

@@ -28,7 +28,7 @@ into a grandchild of a node.  Why can't it be caused by just adding a
 new child to a node?
 
 In the worst case for simple binary trees, every node except one has a
-single chlild. Find some worst case AVL trees.
+single child. Find some worst case AVL trees.
 
 The AIA insertion code is recursive.  What possible ways are there to
 write a non-recursive version?

src/algorithms/extra-info/msort_arr_bup.md

@@ -20,3 +20,14 @@ Geeks for Geeks Link: [**Iterative Merge Sort**][G4GLink]
 
 [G4GLink]: https://www.geeksforgeeks.org/iterative-merge-sort/
 
+
+## Exercises/Exploration
+
+Compare and contrast the sequence of merge operations performed by
+top-down and bottom-up merge sort when the number of elements to be
+sorted is a power of two.
+
+Compare and contrast the sequence of merge operations performed by
+bottom-up and natural merge sort when a) the input is reverse-sorted and
+b) the input is sorted.
+

src/algorithms/extra-info/msort_arr_nat.md

@@ -20,3 +20,14 @@ Happy Coders Link: [**Natural Merge Sort**][HCLink]
 
 [HCLink]: https://www.happycoders.eu/algorithms/merge-sort/#Natural_Merge_Sort
 
+
+## Exercises/Exploration
+
+Compare and contrast the sequence of merge operations performed by
+bottom-up and natural merge sort when a) the input is reverse-sorted and
+b) the input is sorted.
+
+This version of merge sort adapts well to partially sorted input. Can
+you come up with a version of merge sort that adapts well to both
+partially sorted and partially reverse-sorted input?
+

src/algorithms/extra-info/msort_arr_td.md

@@ -20,3 +20,13 @@ Geeks for Geeks Link: [**Merge Sort**][G4GLink]
 
 [G4GLink]: https://www.geeksforgeeks.org/merge-sort/
 
+
+## Exercises/Exploration
+
+Compare and contrast the sequence of merge operations performed by
+top-down and bottom-up merge sort when the number of elements to be
+sorted is a power of two.
+
+Compare and contrast the structure of top-down merge sort with that of
+quicksort.
+