Tuesday, Sept. 12, 2000
Due: Tuesday, Sept. 19, 2000 - before class
Programming. Write (in C, C++, or Java) a small
program for testing and profiling implementations of
Sequential and Binary Search.
Big Oh notation: a small set of functions, tell which
one is Big Oh or little Oh of the other.
The goal is to write a program to compare the running times of
In our case, these two functions are Sequential Search and
Binary Search, which can be implemented by following the
pseudocode description presented in class.
The main program will generate input values for the
search programs: a list L of size n to be searched and
a value x to be looked for in L. Then will call each function in
turn, compute the time it ran, and store it. Iterate this on
several values of n, L and x, store the results in an array and
I recommend that you generate
lists of size n = 2, 4, 8, 16, ... (powers of 2) which consist of the
first n integers in sorted order (1,2, .. , n), and random values
for the search variable x, using the random number generator.
For extra credit, find the value of n when your programs seem to
How to find the time:
I wrote a little program that will serve as a template for this
You can find it
My program uses two functions, one running in
quadratic time, the other in cubic time. It gets the time each
function spent running, and prints them.
You can simply substitute your code for the two search functions,
together with appropriate code for generating input for them. You
might have to calibrate the values of n to get meaningful results.
How to submit
Use submit Hw1 filename from your class account to submit
the program. In class, bring a printed copy of the program and a
printed output from your program (typescript). Use script
for this: ask
one of your colleagues or me, if you do not know how to use
script. On the typescript, in legible handwritting,
please give me some information about
your program: does it compile? execute? does it run correctly,
from all you can see? do the running times seem reasonable?
Make sure your name and class account is on the printout. Comment
For the following pairs of functions, tell whether one is Big Oh
or little Oh of the other. Justify your answer by providing the
appropriate limit calculation.