Assignment 2, due Jan. 26

a) What company introduced the first commercial virtual memory system, in what decade? (0.2 points)

b) What IBM operating system was the first to successfully use virtual memory, in what decade? (0.2 points)

c) What was the first variant of Unix to fully support support virtual memory, in what decade? (0.2 points)

d) What Microsoft operating system was the first to use virtual memory, in what decade? (0.2 points)

e) What Apple operating system was the first to use virtual memory, in what decade? (0.2 points)

You could just as easily use this iterative algorithm, expressed in C:

int fib( int n ) {
        int i = 0
        int j = 1
        while (n > 0) {
                int k = i + j;
                i = j;
                j = k;
                n = n - 1;
        }
        return i;
}

A Problem Write a little tcsh script that computes the n^th Fibonacci number. It can be done recursively or iteratively, so long as the user interface works something like this:

[HawkID@servX]$ fib 3
2

Depending on how you configure your path, you may need to type ./fib Turn in legible readable code, handwritten or machine printed are acceptable. Don't overcomment, but at bare minimum, you should identify the algorithm you are using (recursive or iterative) and the name of the file your script is supposed to be stored in. (2 points).

If you come away from the above assignment hating the Unix shell as a programming language, welcome to the club.

#!/bin/tcsh
# fib i  -- outputs the i'th Fibonacci number
if ($1 < 2) then
    echo $1
else
    @ iminus1 = $1 - 1
    @ iminus2 = $1 - 2
    @ result = `fib $iminus1` + `fib $iminus2`
    echo $result
endif

#!/bin/tcsh
# fib i  -- outputs the i'th Fibonacci number
@ count = $1
@ i = 0
@ j = 1
while ($count > 0)
    @ k = $i + $j
    @ i = $j
    @ j = $k
    @ count = $count - 1
end
echo $i