Tentamen/Exam
TDDC32 Design och implementering av programmodul i Java
TDDC32 Design and implementation of a software module in Java
2009–08–25
14.00 – 18.00
• No help materials are allowed, except for an English dictionary.
• You may answer in Swedish or English.
• Total number of credits is 24. Limits:
3: 12p, 4: 16p, 5: 20p.
• Jour (person on duty): Jonas Wallgren.
1
1
OOA&OOD
Explain what is ment in OOA and OOD by the following concepts/”slogans”:
a)(1.5p) Divide and conquer
b)(1.5p) Iterate and increment
c)(1.5p) Reuse and recycle
d)(1.5p) Strong cohesion and low coupling
2
UML
Describe the following situation using a class diagram (3p):
A city has a number of districts.
A district consists a number of blocks.
A block consists of number of buildings.
A dwelling-house is a building.
An office building is a building.
A block of flats is a dwelling-house.
A villa is a dwelling-house.
A block of flats is occupied by a number of families.
A villa is occupied by one family.
A family consists of several persons.
An employee is a person.
An office building contains several employees.
2
3
AVL
a)(1.5p) Construct the AVL tree from the keys (in the given order) 9 6 7 2 1 11 3 15 4 5.
You only need to show the final result.
b)(1.5p) Remove 30 from the following AVL tree. Draw the tree transformations step by step.
20
/\
/ \
/
/
\
\
10
30
/\
/\
/ \
/ \
7
14 25 35
/ \
/
/
3
9 12 22
/
1
4
Splay
a)(1p) When is a splay tree better than an AVL tree and why is it better?
b)(2p) Construct a splay tree from the keys (in the given order) 4 5 6 7 1 2 3.
Show the tree after each insertion is completed.
3
5
(a,b)-tree
a)(2p) Show what happens step by step when you remove the values 10, 44, 20
from the following (2,4)-tree:
+----+
| 20 |
+----+
/
\
/
\
+----+
+----+----+----+
| 10 |
| 30 | 40 | 50 |
+----+
+----+----+----+
|
|
/
|
|
\
+---+ +----+ +----+ +----+ +----+ +----+
| 3 | | 18 | | 23 | | 39 | | 44 | | 59 |
+---+ +----+ +----+ +----+ +----+ +----+
b)(1p) What is a and b in “(a,b)-tree”? How are they related?
6
Hash
a)(2p) In a hashtable using linear hashing of size 11 insert: 7, 3, 18, 31, 50, 6, 4, 12, 25, 14
in that given order.
Describe where each element is placed and comment/explain why.
b)(1p) What is the complexity of introducing one piece of data into the hashtable?
In what situations are hashtables preferred to trees?
7
Skip
Build a skip list for the elements 1, 3, 5, 7, 2, 4, 6, 8 in that order.
The results of the coin tossing are (H=head, T=tail) H, H, T, H, T, T, over and over again. (3p)
4