Topic 1: Help with P5 (as requested)

* hints on Bubble Sort
    * 2 For Loops
    * outer loop: N-1 passes
    * inner loop: pair-by-pair comparisons and swaps

------------------------------------------------------------
Topic 2: Pointer Notation: Review

        Consider this code:

        int x;
        int *p1, *p2, *p3;
        int list[4]; 

        p1 = &list[2];
        p2 = &x;
        p3 = list + 1;
        //not shown: code to give list[0-3] and x values ...

        Here is the resulting view of memory:

 
                          values       addresses
                     -----------------
                 x   |     1000      | 200
                     -----------------
                    ...             ... 
                     -----------------
                 p1  |     502       | 300
                     -----------------
                 p2  |     200       | 301
                     -----------------
                 p3  |     501       | 302
                     -----------------
                    ...             ... 
                     -----------------
           list[0]   |     10        | 500
                     -----------------
           list[1]   |     20        | 501
                     -----------------
           list[2]   |     30        | 502
                     -----------------
           list[3]   |     40        | 503
                     -----------------

   What are the values of the following variables and expressions?

     *p1                     *p2

     *p3                     *(p2 + 1)
 

     list                    *list


     list + 2                *(list +2)

     &p1 

     p3[2]                    *(p3-1) 
------------------------------------------------------------
Topic 3: Calling a function on part of an array.

* Consider this function:

  int sumArray(int list[], int n)
  {
        int i, sum = 0;

        for (i = 0; i < n; i++)
            sum += list[i];

        return sum;
  }

* Now consider the main function:

  int main()
  {
      int scores[10];
      int sum1, sum2;

      /* not shown: code to fill up array */

      sum1 = sumArray(scores, 10); 

      sum2 = sumArray(scores+2, 8);  
    ...
   }

   * notes:
        * scores+2 is the address of scores[2],
          equivalent to &scores[2]
        * this is memory just after the 2nd call:
       
                     -----------------
          scores[0]  |               | 50
                     -----------------
          scores[1]  |               | 51
                     -----------------
          scores[2]  |               | 52
                     -----------------
          scores[3]  |               | 53
                     -----------------
             ...
 
 
          list       ------------------
                     |     52          | 100
                     ------------------


        * thus, the function simply starts its loop
          at scores[2], instead of at scores[0]

------------------------------------------------------------ 
Demonstration:

2 ways to write a function called fill that inserts
the same value "num" into each element of an array.

Exercise 1:
 
   void fill(int list[], int n, int num)
   {
        int i;
 
        for (i = 0; i < n; i++)
            list[i] = num;
    }
 
Exercise 2:
 
   void fill(int *p, int n, int num)
   {
        int i;
 
        for (i = 0; i < n; i++) {
            *p = num;
            p++;
        }
   }
 
------------------------------------------------------------
                          * * * * *