/***********************************************************************
 * CS 141, Spring '01, Exam 2: Sample Answers
 *
 * These are possible answers to the questions on the exam.  They are
 *   not the only possible right answers, nor are they necessarily the 
 *   most concise answers.
 * If you find an error, please notify me at tuinstra@clarkson.edu
 *   right away.  For any error that may be found, the first three
 *   persons to report it to me will receive an extra 2 points per
 *   error (up to a maximum exam score of 100, and up to a maximum
 *   of 5 extra points).
 * The `include' statements below are not required in your answers.
 *   They are included here so that this file can actually be compiled.
 *
 ***********************************************************************
 */
#include <iostream.h>
#include <stdlib.h>
#include <fstream.h>

/*======================================================================
 * Problem 1 A
 =======================================================================
 */
int sum_part( int arr[],       /* array of integers */
              int item_count,  /* how many items in the array */
              int start_pos,   /* add up scores starting from here... */
              int end_pos )    /* ... and ending here */
{
    int sum;
    int i;
    
    sum = 0;
    for( i = start_pos; i <= end_pos; ++i )
        sum += arr[i];
    
    return sum;    
}

/*======================================================================
 * Problem 1 B
 =======================================================================
 */

int main( )
{
    int scores[101];    /* indexes from 0 to 100 require 101 entries */
    int B_count;        /* holds how many got a `B' */
    int i;              /* array index and loop control */
    
    /* Instruct and prompt the user.  Your program was not required
     * to do this.
     */  
    cout << "Please enter how many students got a score of 0," << endl;
    cout << "  followed by how many got a score of 1,"         << endl;
    cout << "  followed by how many got a score of 2, and so"  << endl;
    cout << "  on up to how many got a score of 100.  If no"   << endl;
    cout << "  students earned a given score, enter 0 (zero)"  << endl;
    cout << "  for that score's number.  You will need to"     << endl;
    cout << "  enter 101 numbers.  Please enter them now."     << endl;
    
    /* The user will now enter 101 numbers.  We read them in and put
     *   them into their respective array positions.
     */
    for( i = 0; i <= 100; ++i )
        cin >> scores[i];
    
    /* Now calculate how many students got scores from 80 to 89 */
    B_count = sum_part(scores, 101, 80, 89);
    
    /* Print out the result */
    cout << "There were " << B_count << " students who got a B\n";
    
    return (EXIT_SUCCESS);
}

/*======================================================================
 * Problem 2
 =======================================================================
 */

bool more( char str[] )
{
    int i;      /* index into string */
    int count;  /* how many letters are the same as the first letter */
    
    count = 0;
    
    /* The loop below will always count the first character, since
     *   it's equal to itself!
     */
    for ( i = 0; str[i] != '\0'; ++i )
    {
        if ( str[i] == str[0] )
            ++count;
    }
    
    /* A count of one means the only character matching str[0]
     *   was itself.  Other positive counts mean there were other
     *   characters which matched str[0].  A count of 0 occurs if
     *   (and only if) the string is empty; in this case we'll 
     *   return `false' (your function is not required to handle the
     *   empty string this way).  Negative counts are not possible.
     */
    if ( count > 1 )
        return true;
    else
        return false;
}

/*======================================================================
 * Problem 3
 =======================================================================
 */

/* Here, we consider `positive' to mean integers strictly greater
 *   than zero.  We will also give credit if your answer treats 0 as
 *   a positive number.
 */

void copypos( ifstream & in, ofstream & out )
{
    int item;   /* holds numbers read from the input stream */
    
    while ( in >> item )
    {
        if ( item > 0 )             /* write positives, ignore others */
            out << item << endl;
    }
}

/*======================================================================
 * Problem 4 A
 =======================================================================
 */

class university
{
  private:
    char    name[201];      /* name of the university, 200 chars max */
    int     women;          /* female enrollment */
    int     men;            /* male enrollment */
    
  public:
    int     num_students( );    /* Returns total enrollment.
                                 * NOTE: no parameters needed!! 
                                 */
};

/*======================================================================
 * Problem 4 B
 =======================================================================
 */

int university::num_students( )
{
    return (women + men);       /* Since this is a member function, it
                                 * has direct acess to the data fields.
                                 */
}

/*======================================================================
 * Problem 4 C
 =======================================================================
 */
 
bool more_students( university & u1, university & u2 )
{
    if ( u1.num_students() > u2.num_students() )
        return true;
    else
        return false;
}