Educational Objectives: After successfully completing this assignment, the student should be able to accomplish the following:
Operational Objectives: Create a project that computes the mean and median of a sequence of integers received via standard input.
Deliverables: Four files: stats.h, stats.cpp, main.cpp, makefile. Note that these files constitute a self-contained project.
Given a finite collection of n numbers:
Note that to find the median of a collection of data, it is convenient to first sort the data, that is, put the data in increasing (or non-decreasing) order. Then the median is just the middle datum in the sorted sequence (or the average of the two middle data, if there are an even number).
One of the more intuitive sort algorithms is called Insertion Sort, which operates on an array a[0..n-1] of elements. The idea is to "insert" the value of a[i] into the sub-array a[0..i-1] at the largest possible index that results in the expanded sub-array a[0..i] sorted. We insert at the highest possible index in order not to place the value ahead of any previously inserted elements with the same value. The subarray a[0..i-1] is assumed to be sorted at the beginning of each insertion step. The base case consists of a one-element array a[0..0], which is always sorted.
Here is a "pseudocode" description of the algorithm:
for (i = 1; i < n; ++i) t = a[i]; // remember the value in a[i] starting at j = i while j > 0 and t < a[j - 1] copy a[j-1] to a[j] j = j - 1 end while // now we have t >= a[j] copy t into a[j] end for
The inner loop copies all elements in a[0..i-1] up one index until the correct place for t is found. Then put t in that place.
Create and work within a separate subdirectory cop3330/hw2. Review the COP 3330 rules found in Introduction/Work Rules.
Copy these files
LIB/hw2/makefile LIB/hw2/hw2submit.sh
from the course distribution library into your project directory.
Create three more files
stats.h stats.cpp main.cpp
complying with the Technical Requirements and Specifications stated below.
Turn in four files stats.h, stats.cpp, main.cpp, and makefile using the hw2submit.sh submit script.
Warning: Submit scripts do not work on the program and linprog servers. Use shell.cs.fsu.edu to submit projects. If you do not receive the second confirmation with the contents of your project, there has been a malfunction.
The project should compile error- and warning-free on linprog with the command make stats.x.
The number of integers input by the user is not known in advance, except that it will not exceed 100. Numbers are input through standard input, either from keyboard or file re-direct. The program should read numbers until a non-digit or end-of-file is encountered or 100 numbers have been read.
Once the input numbers have been read, the program should calculate the mean and median and then report these values to standard output.
The source code should be structured as follows:
float Mean (const int* array, size_t size); // calculates mean of data in array float Median (int* array, size_t size); // calculates median of data in array void Sort (int* array, size_t size); // sorts the data in array
The source code should be organized as follows:
The Sort() function should implement the Insertion Sort algorithm.
When in doubt, your program should behave like the distributed executable examples in stats_i.x and stats_s.x in area51. Identical behavior is not required, but the general I/O behavior should be the same. In particular, the data input loop should not be interupted by prompts for a next datum - this will make file redirect cumbersome. Just ask for the data one time, then read until a non-digit or end of file is encountered.
make ranint.x
and then execute. Note that the program expects 3 command line arguments - (1) file name, (2) upper bound on size of integers, and (3) number of elements to generate. It will remind you if you forget. Here are examples:
~/3330/hw2>ranint.x ** required arguments: 1: filename 2: upper bound on absolute size ('0' means no upper bound) 3: count of items ** try again ~/3330/hw2>
(Forgot to give arguments.)
~/3330/hw2>ranint.x d1 99 51 Results stored in file d1 range: -99 .. 98 count: 51 ~/3330/hw2>ranint.x d2 99 52 Results stored in file d2 range: -99 .. 98 count: 52 ~/3330/hw2>