CS 60 Slides

1
ACM
Mock Contest Problems Notes
straightforward but ugly
0 - 0
(1) Spreadsheet
1 - 0
(2) Tetris/tiling
depth-first search
12 - 2
(3) Toil problem
first problem for most teams
8 - 3
(4) To bet or not to bet
dynamic programming
8 - 0
(5) Siscos galaxy
graph problem -- shortest path
4 - 0
(6) Poison
straightforward but long
Top four teams
Problem Statistics correct - inc.
Team Time MBASDL 5
715.00 CLTWPV 4 444.00 RRNEDK 4
471.00 EHMVKR 4 475.00
2
ACM So CA Regionals
Top 6 places
solved
total time (approx.)
1. Caltech 2. UCSD 3. Asuza Pacific Univ.
4. UCSD 5. HMCs Saturation Bombing 6.
UNLV 9. HMCs Judges 14. HMCs Infinite
Monkeys (53 teams competed)
4/6 3/6 3/6 3/6 3/6 3/6
12h. 50m. 7h. 20m. 9h. 25m. 9h. 30m. 9h.
35m. 10h. 30m.
Problem Statistics
Problem Solutions Submissions
1 2 3 4 5 6
0 41 10 7 1 2
8 140 26 38 3 11
3
Contest References
No electronic devices are permitted. Any written
references are OK.
usefulness

• Coding references

Known, solved problems
language/library references
man pages are available...

• Environment references

.emacs .vimrc .bashrc
Things youd otherwise take for granted...

• Algorithms references

CLR, Knuth
4
Contest Strategy

• Solve the simplest problem first
• Code with someone looking over your shoulder.
• Print code and debug from the printout.
• Use the preliminary time to get used to the
  system
• Remember that debugging is worth 20 minutes

vs. starting to type code in immediately
they will catch bugs and know enough to debug
later
better than tying up the terminal
printing, submitting, the computing environment,
and other available commands
but only 20 minutes!
Other suggestions?
5
International Problem

• Crossword puzzle construction

10 x 10 grid
6
International Problem

• Crossword puzzle construction

10 x 10 grid
word starting points
4 1 1 D 3 1 A 5 1 A 3 5 D
7
International Problem

• Crossword puzzle construction

10 x 10 grid
word starting points
4 1 1 D 3 1 A 5 1 A 3 5 D
coffee easeful flays safety tusks
one more word than needed
8
International Problem

• Crossword puzzle construction

c
10 x 10 grid
o
f
word starting points
f
4 1 1 D 3 1 A 5 1 A 3 5 D
e
e
coffee easeful flays safety tusks
one more word than needed
9
International Problem

• Crossword puzzle construction

c
10 x 10 grid
o
f
l
a
y
s
word starting points
f
4 1 1 D 3 1 A 5 1 A 3 5 D
e
e
coffee easeful flays safety tusks
one more word than needed
10
International Problem

• Crossword puzzle construction

c
10 x 10 grid
o
f
l
a
y
s
word starting points
f
a
4 1 1 D 3 1 A 5 1 A 3 5 D
e
f
e
e
t
y
coffee easeful flays safety tusks
one more word than needed
11
International Problem

• Crossword puzzle construction

c
10 x 10 grid
o
f
l
a
y
s
word starting points
f
a
4 1 1 D 3 1 A 5 1 A 3 5 D
e
a
s
e
u
l
f
e
e
t
y
coffee easeful flays safety tusks
one more word than needed
Output the unused word(s)
Trial 1 tusks
12
International Problem

• Crossword puzzle construction

e
10 x 10 grid
a
s
a
f
e
t
y
word starting points
e
u
4 1 1 D 3 1 A 5 1 A 3 5 D
f
l
a
y
s
u
k
s
l
coffee easeful flays safety tusks
one more word than needed
Output the unused word(s)
Trial 1 tusks coffee
13
ACM
Mock Contest Problems Notes
straightforward but ugly
0 - 0
(1) Spreadsheet
1 - 0
(2) Tetris/tiling
depth-first search
12 - 2
(3) Toil problem
first problem for most teams
8 - 3
(4) To bet or not to bet
dynamic programming
8 - 0
(5) Siscos galaxy
graph problem -- shortest path
4 - 0
(6) Poison
straightforward but long
Top four teams
Problem Statistics correct - inc.
Team Time MBASDL 5
715.00 CLTWPV 4 444.00 RRNEDK 4
471.00 EHMVKR 4 475.00
14
Contest References
No electronic devices are permitted. Any written
references are OK.
usefulness

• Coding references

Known, solved problems
language/library references
man pages are available...

• Environment references

.emacs .vimrc .bashrc
Things youd otherwise take for granted...

• Algorithms references

CLR, Knuth
15
Contest Strategy

• Solve the simplest problem first
• Code with someone looking over your shoulder.
• Print code and debug from the printout.
• Use the preliminary time to get used to the
  system
• Remember that debugging is worth 20 minutes

vs. starting to type code in immediately
they will catch bugs and know enough to debug
later
better than tying up the terminal
printing, submitting, the computing environment,
and other available commands
but only 20 minutes!
Other suggestions?
16
International Problem

• Crossword puzzle construction

c
10 x 10 grid
o
f
l
a
y
s
word starting points
f
a
4 1 1 D 3 1 A 5 1 A 3 5 D
e
a
s
e
u
l
f
e
e
t
y
coffee easeful flays safety tusks
one more word than needed
Output the unused word(s)
Trial 1 tusks