Name: ____________________________________________________ Alpha: _____________________

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1. [20pts] First run the following commands in the terminal:

   ~$ echo "1 2 3 4" > in.txt
   ~$ ls
   ~$ cat in.txt
   

   You will see a new file in.txt has been created, which contains four numbers (i.e., 1, 2, 3, and 4).
   You don't need to know this, but if you're curious: Roughly, the echo command works like cout in the terminal (i.e., output a string to the terminal), and the redirection operator > redirects (i.e., saves) the terminal output to a file.
   Now, consider the following code. The code creates a file out.txt, and then it simply tries to read all numbers from in.txt and write them to out.txt.

   
   #include <iostream>
   #include <fstream>
   
   using namespace std;
   int main() {
     ifstream fin("in.txt");
     ofstream fout("out.txt");
   
     int n;
     while( fin ) {
       fin >> n;
       fout << n << " ";
     }
     fout << endl;
   
     return 0;
   }
   

   1. [5 pts] Copy and paste the above code into a new file called hw14_1.cpp. Then compile and run the program as follows:

      ~$ g++ hw14_1.cpp
      ~$ ./a.out
      ~$ cat out.txt
      

      Write the result of the last cat command (i.e., the contents of out.txt).

   2. [5 pts] Explain why the code does not work as we expected it to. If necessary, revisit the notes on File I/O (see the section "When file ends").

   3. [10 pts] Fix the above code by annotating it.

2. [80pts] Write a program that reads in a file like this:

   3
   4
   23 788 12 -6 
   0 2 -337 -8923 
   25656 -89 0 1

   that contains a table of integers in unformatted text, and writes out a file output.html that shows the same table in html, which looks like this

   <table border=2> <tr><td>23</td><td>788</td><td>12</td><td>-6</td></tr> <tr><td>0</td><td>2</td><td>-337</td><td>-8923</td></tr> <tr><td>25656</td><td>-89</td><td>0</td><td>1</td></tr> </table>

   and renders like this

   23 788 12 -6 0 2 -337 -8923 25656 -89 0 1

   You must assume:

   • The file is named input.txt.
   • The first line of the file tells you how many rows are in the table.
   • The second line tells you how many columns.
   • The subsequent lines contain the values to appear in the table.
   Look at w3 tables intro if you need a little help with tables in HTML.
   
   Turn In a printout of your source code, and a printout of the table rendered by the browser when you open the file (use ctrl-o in your browser to open a file) output.html produced by your program with this input file. The result should look like:
   

   23	788	12	-6	7
   0	2	-337	-8923	7
   25656	-89	0	1	7
   8	67	14	-2	0