Problem: Read data from file of unknown size, store in memory for processing

nums.dat     lotsauNums.dat
+----+ 	     +----+ 
| 9  | 	     | 9  | 
| 86 | 	     | 86 | 
| 63 | 	     | 63 | 
| 47 | 	      ...     in here there could be 5 million more numbers!!!
| 81 | 	     | 47 | 
+----+ 	     | 81 | 
	     +----+ 


For the final exam, know these three options:

(1) Static arrays:


    size determined at compile time
    size is FIXED.
    space allocated on stack

  advantage: easy
  disadvantage: wasteful of space


(2) Dynamic arrays 

    size determined at run time
    space allocated on heap

  advantage: easy
  disadvantage: must know size in advance

 
(2b)

  One way around "needing to know size in advance" is
  to 
    first read through the file in its entirety, 
    but don't store anything... just count how many
    numbers there are.

    then, allocate an array big enough.

  Disadvantage: Doubles the time required to
     read all the data.

  
(3) Linked Lists

    size determined on the fly...
    space is on the heap

    grow or shrink on demand... 

    disadvantage: detailed
       also: overhead of 32-bits per value stored...
             "next pointers"