Chapter 9: Programming Exercises

 1. Write a program that prompts for and reads a line of
    text and uses a stack to reverse that line of text.
    The program then shows each reversed line on the
    screen.  The program continues prompting, reading and
    displaying until the user enters 'end' at the beginning
    of the line input prompt.

 2. Write a program to compress an ASCII text file and to
    recover the original text from the compressed text.
    Whether the program is compressing or uncompressing the
    text will be indicated by a command line switch.  The
    switch  **-c** will indicate that compression is to
    take place.  The switch  **-u** will indicate that
    uncompression is to take place.  The text file will be
    read by redirection of  **stdin** on the command
    line.  The compressed text will be written to a file by
    using redirection of  **stdout** on the command line.

    Compression squeezes a given amount of information so
    that it requires less storage.  We consider a bit
    compression technique in which eight characters are
    compressed into seven bytes, resulting in a 12.5%
    saving in storage.  This technique exploits the fact
    that no ASCII letter or punctuation mark uses the
    eighth bit of a byte.  Therefore, the eighth bit of
    each of the seven bytes can be used to sotre the eighth
    character.

    For example, the word  **ziggurat** is represented in
    eight bytes as

    byte 0    0111 1010      z
    byte 1    0110 1001      i
    byte 2    0110 0111      g
    byte 3    0110 0111      g
    byte 4    0111 0101      u
    byte 5    0111 0010      r
    byte 6    0110 0001      a
    byte 7    0111 0100      t

    The seven significant bits of byte 0 can be distributed
    into the seven unused positions of bytes 1 through 7.
    The seven remaining bytes then appear as

    byte 1    1 110 1001
    byte 2    1 110 0111
    byte 3    1 110 0111
    byte 4    1 111 0101
    byte 5    0 111 0010
    byte 6    1 110 0001
    byte 7    0 111 0100

 3. Fill in the missing pieces where indicated.

#include
#include
#include
#include

#define MAX_N_A 80
#define MAX_SSN 11+1

struct EmpPayrollInfo
{
    int hours;
    int rate;
};

struct EmpPersonalInfo
{
    char *name;
    char *address;
    char  ssn[MAX_SSN+1];
    int   id;
    EmpPayrollInfo *payroll;
};

int main()
{
char buffer[MAX_N_A+1];
int i, len;
EmpPersonalInfo *emp;
    //
    // allocate the space for the structure
    //
    emp = _______________// fill this                           ________________________
       ___________________//   fill in what goes        ______________

    //
    // prompt for the name and then store it in the
    // structure
    //
    cout << "Enter employee's name: ";
    fgets(buffer, MAX_N_A, stdin);
    len = strlen(buffer);
    //
    //   allocate space for the name
    //
    emp->name = _________________// fill this         ________________
       ______________//   fill in what goes        ___________________

    memset(emp->name, 0, len);
    strncpy(emp->name, buffer, len-1);
    //
    // prompt for the address and then store it in the
    // structure
    //
    ______________________// fill in what goes     _____________
    //
    //  prompt for the ssn and store it in the structure
    //
    _____________________// fill in what goes     ______________
    //
    // prompt for the emp id and store it in the structure
    //
    ____________________// fill in what goes     _______________
    //
    // prompt for some number of weeks of payroll data
    //
    cout << "How many weeks of payroll data? ";
    cin >> len;
    //
    // note: this basically allocates an array of 'len'
    // size
    //
    emp->payroll = ___________// fill in what goes here     ________
    _________________________// fill in what goes     __________
    //
    //   fill in the array
    //
    for (i=0; i<< "Enter hours for week " << i+1 << ": ";
       __________________// fill in what goes        ______________
       cout << "Enter rate  for week " << i+1 << ": ";
       _________________// fill in what goes        _______________
    }
    //
    // print out all employee info
    //
    cout << ___________// fill in what goes             ________________
    //
    //   loop to print array held data
    //
    for (i=0; i<< __________// fill in what goes
               _____________
    }
}