part1.cpp
) that converts between Dollars, Euros
and Pounds. The program reads input from the user in the
following format:
Convert amount currency_1 to currency_2
and prints results in the obvious way. Here are a couple of
sample runs:
~$ ./part1 Convert 3.50 Euros to Dollars ~$ ./part1 Convert 3.50 Euros to PoundsHere are the conversion rates you'll need: 1.00 Dollar is Euros and 1.00 Dollar is Pounds.
Important: do not write if statements for every single pairwise combination (e.g., dol-euro, dol-pound, euro-dol, euro-...). Instead, always convert the first given currency to Dollars, and then convert Dollars to the second currency. This avoids an explosion of if statements as you move to Part 2 when another currency is added to the mix. Instead of n^2 if statements, you'll only need n*2 statements (n is the number of possible currencies).
~/bin/submit -c=SI204 -p=lab03 part1.cpp
part2.cpp
)
to allow for Canadian
dollars as well (1.00 Dollars US
is Dollars Canadian).
Now the user can't simply put "Dollars" in the input,
it must be either "Dollars US" or "Dollars Canadian".
Here are a couple of sample runs:
~$ ./part2 Convert 3.50 Euros to Dollars Canadian ~$ ./part2 Convert 11.72 Dollars US to Dollars Canadian
Submission: If you're finished before lab ends, please demo for your instructor. Also submit via the class submit script as follows:
~/bin/submit -c=SI204 -p=lab03 part1.cpp part2.cpp
part3.cpp
)
that
reads in three points from the user
and prints output that the user can
put in a file to give the program "gnuplot"
to produce a plot
showing the triangle defined by the three
user-input points along with its bounding
box, i.e. the smallest rectangle aligned
with the coordinate axes that contains the
triangle.
Gnuplot is a standard tool for creating plots. Its input is simply a text file of points, one per line, given by the point's x-coordinate, followed by a space, followed by its y-coordinate. Gnuplot will draw a mark at each point, and connect successive points with segments, as long as they are not separated by blank lines. Note: this means that drawing a closed figure (like a triangle) requires repeating the first point at the end of the input.
Here's a sample of running the program and using gnuplot to plot the results. Note: please print the lines defining the bounding box before the lines defining the input triangle. This is for automatic grading purposes, not because gnuplot cares.
sample run |
~/$ ./part3 (-1.1,-0.5) (1,3.3) (2.7,-1.1) -1.1 -1.1 -1.1 3.3 2.7 3.3 2.7 -1.1 -1.1 -1.1 -1.1 -0.5 1 3.3 2.7 -1.1 -1.1 -0.5 |
after copy&pasting output into a new file named tmp ... |
[copy&paste the output into a new file named |
gnuplot's output |
~/bin/submit -c=SI204 -p=lab03 part1.cpp part2.cpp part3.cpp
part4.cpp
)
that reads three lengths from the
user displays the type of triangle that is formed by the input according to
both kinds of classification. E.g. "This is a obtuse scalene triangle"
cmath
library has a function asin()
that computes the arcsine of an angle. Enter
man asin
on the command line for documentation.
We have a bit of a problem in that for any positive angle $\theta$
less than $\pi/2$, we have that $\sin(\theta) = \sin(\pi - \theta)$.
Thus, when we use $\theta$ = asin(w)
for positive w
,
we don't know whether we really want the angle
$\theta$ or $\pi - \theta$.
In our triangle case, we cans fix things like this: if the three angles we calculate (A, B and C) sum up to a lot less than $\pi$ (in fact, we should probably check that the sum is less than 3), we replace the angle opposite the longest side with $\pi$ minus that angle. So, for example, if $A$ is opposite the longest side, then we replace $A$ with $\pi - A$.
BTW: as long as you're including cmath
, the
constant M_PI
gives you a high-precision double
representation of $\pi$.
Also, the function sqrt( )
computes square roots.
Example executions are shown below:
~/$ ./part4 Enter side lengths: 1 2 3 Error! these lengths violate the triangle inequality! ~/$ ./part4 Enter side lengths: 1.5 2 3 This is a obtuse scalene triangle. ~/$ ./part4 Enter side lengths: 2 2 3 This is a obtuse isosceles triangle. ~/$ ./part4 Enter side lengths: 2 2 2 This is a acute equilateral triangle. ~/$ ./part4 Enter side lengths: 2 2 1.5 This is a acute isosceles triangle.
Submission: If you're finished before lab ends, please demo for your instructor. Also submit via the class submit script as follows:
~/bin/submit -c=SI204 -p=lab03 part1.cpp part2.cpp part3.cpp part4.cpp