SPA 1: Fluid Tracking

A key health indicator for hospitalized patients is ratio of fluid intake (IVs, drinks, Popsicles, etc.) to fluid output (urine, blood loss, etc.). This metric is useful because it can identify dangerous issues such as dehydration and renal failure without requiring expensive, invasive tests. See this site for more details if you are interested. For this assignment, you are going to write a program which keeps a running tally of intakes and output and flags when the differential is 1 liter or more, a commonly used value. This will give you experience with writing basic loops and doing simple computations in C++.

Unlike most other assignments, it is fine to work together with another student on this assignment. That is, we will not be examining your solutions for plagiarism. It would be good to document who you worked with in your code (as described in the integrity policy), but we will not check for this assignment.

The input to your program will be a simple log for a given patient. Each log entry is on its own line and will have the form

        time item amount-in-milliliters

For example:

        7:00 iv 200
        7:30 orange_juice 100
        8:00 iv 300
        13:15 water 150
        14:05 urine 100
        15:05 bloodloss 50
        15:30 soup 400
        15:30 coffee 200
        15:50 diarrhea 350

(You have to respect those who do these measurements!) For simplicity, you can make the following assumptions:

• Each line always has three words (sequences of characters separated by spaces) with the first word being the time, the second the item, and the third the amount in milliliters. You do not have to check for missing or illegal fields. This includes not checking times to make sure there is both an hour and a minute.
• The outputs are always one of "urine", "bloodloss", and "diarrhea". Any other item is treated as an input.
• Times are likely to be in order, but they may not be. There is no requirement to check if they are in order.

The program reads the data (with no prompt) and prints a message of the form

        after consuming UUU at VVV, intake exceeds output by XXX ml

whenever the accumulated total is at least 1000 milliliters (one liter). In this output, UUU is the item name, VVV is the time, and XXX is the accumulated total. After all data is read, print a message of the form

        the final fluid differential is YYY ml

where YYY is the final total. As an example, running your program on the above input will result in the output

        after consuming soup at 15:30, intake exceeds output by 1000 ml
        after consuming coffee at 15:30, intake exceeds output by 1200 ml
        the final fluid differential is 850 ml

You should do some quick addition (by hand) on the above example to confirm these numbers are correct! Some further notes:

• Once the total fluid intake differential is 1000 or more, the program will keep printing the message about the differential until all input is exhausted.
• In this case, two intakes happen at the same time. Simply treat them as separate items.
• Only print messages about high fluid differentials on consumption events, not fluid loss events.
• If there are no inputs, the program will just print a final differential of 0 ml.

Stage 1

We will be consistent about providing multiple stages for assignments. You can receive credit for each stage even if nothing else works. You are advised to complete your solution in stages, but a working solution will pass all stages.

Stage 1 of this assignment is complete when you can read one line of input and print the fluid intake of that one line using the format of the expected final message. You can assume this line is an intake (rather than an output), so you do not need to use if statements or while loops to get this stage working. For example, if the text file contains just the line

        10:30 coffee 175

then the output would be

        the final fluid differential is 175 ml

You can implement this just by reading two strings and an integer and printing the integer in the above format. Test 1 will confirm this case. You can receive 40% credit on this assignment simply by passing test 1.

Note that you can read multiple pieces of information in an input statement. For example, if your input is

        Cathy Xhu 19

and you have

        string first, last;
        int age;

then

        cin >> first >> last >> age;

will set first to "Cathy", last to "Xhu", and age to 19. This style of reading will read text up to the next whitespace (newline, space, etc.) and then store it in the destination. There is no need to read whole lines and break them apart for an assignment like this.

Stage 2

Extend your solution to process the full input. That is, write an end-of-file controlled loop that reads the data. Remember that the general pattern for such a loop in C++ is

        read
        while ( cin ) {
          process
          read
        }

It is important to read both before the loop header and at the end of the loop. Do not try to have just a single read - it may appear to work at first, but if you look closely at your output you will see errors.

If you have a program that reads until end-of-file and run that program in CLion, you will need a way to indicate that you have entered all data. Click on the console window and press Control-D (hold down the Ctrl button and press D). This will send an end-of-file message to the program. However, entering large amounts of text in the console window is error-prone. Another way is to configure CLion to read input from a file instead. If your project is open in CLion, click on the three vertical dots next to the debug symbol, select Edit... (for the run configuration), select the Redirect input from box, and browse to a file like 2.in. Then you can run and debug your code as usual with the input coming from this file instead of the console (that is, instead of the keyboard).

Submitting

• Submit your solution (as 1fluids) using esubmit. You are expected to match this output exactly, though you can get partial credit if there are some errors.
• Ensure your code meets the coding standard, including the banner comment for the file. There are no other documentation requirements for this assignment. In addition, there is no requirement to keep main less than 15 lines - you do not need to write additional functions (other than main) for this assignment.
• If requested by your instructor, answer the reflection questions in Canvas.

Common Issues

• esubmit claims my output has differences but I do not see any. This is usually caused by not printing an endl after your last line of output:

          cout << "last line" << endl;
  

  (Operating systems utilities typically assume all text lines are terminated by the appropriate end-of-line characters. It is good practice to always line-terminate your output. Recall endl generates the right line terminators for your system.)
• Be careful about how you write the end-of-file controlled loop. It's common to try a non-standard pattern like

          while ( not end-of-file ) {
             read
             process
          }
  

  This does not work in C++ because end-of-file becomes true after attempting to read data. The pattern that does work is

          read
          while ( not end-of-file ) {
             process
             read
          }
  

  This means the code to read data is repeated. This is what works! If the read operation is complex, then put it into a function and call that function to do the work.
• If your code is not compiling in CLion, you might try compiling it by hand:

          g++ -std=c++17 main.cpp
  

  This will create the file a.out (on Linux) or a.exe (on Windows). Linux users run it with ./a.out and Windows with .\a.exe.