Exercises

Author: lee-naish

src/algorithms/extra-info/MSDRadixSortInfo.md

@@ -25,3 +25,17 @@ Sort)
 The coding of partition used in AIA is based on the coding in quicksort.
 Compare and contrast the two.  What other approaches to coding partition
 could be used?
+
+In quicksort, the maximum stack size depends greatly on the order of the
+input data. For MSD radix sort, what influence does the input order have
+(if any), and why?
+
+Compare and contrast the behaviour of quicksort and MSD radix sort when
+there are many duplicate keys. When is quicksort better (if ever)? When
+is MSD radix sort better (if ever)?
+
+In quicksort, the runtime generally is not affected by the size of the
+numbers being sorted: we can square each number and the run time is
+the same.  For the AIA version of MSD radix sort, what is the expected
+affect on run time if we square each number in the input?
+

src/algorithms/extra-info/QSM3Info.md

@@ -35,3 +35,12 @@ an array element) was written so as to minimise the number of instructions
 executed by the hardware. Hardware has changed a lot since then! Look
 into some more recent efficient ways of coding partition.
 
+Give two examples of input to quicksort which best cases for median
+of three partitioning but are worst cases for the simple version of
+quicksort.
+
+Can you construct a worst case input for median of three quicksort for
+the number 1 to 12?  For example, the first call to partition takes
+the median of 3, 2 and 1, the second takes the median of 5, 4 and 3,
+the next has 7, 6 and 5 etc.
+

src/algorithms/extra-info/StraightRadixSortInfo.md

@@ -21,3 +21,13 @@ Geeks for Geeks Links: [**(Straight/LSD) Radix Sort**][G4GLink] and
 [G4GLink]: https://www.geeksforgeeks.org/radix-sort/
 [G4GLink2]: https://www.geeksforgeeks.org/counting-sort/
 
+## Exercises/Exploration
+
+In *counting sort*, temporary array **B** is filled by scanning array
+**A** from right to left. If it was scanned from left to right, array
+**B** would still end up sorted on the digit in question.  What would
+the affect be on the radix sorting if left to right scanning was used?
+
+Look up how sorting punched cards has been done historically. Card
+sorting machines used LSD radix sorting! How could you sort a deck of
+playing cards using LSD radix sorting?