1,2c1
<              P R E L I M I N A R Y    S P E C I F I C A T I O N
< 
---
>                  R E V I S E D    S P E C I F I C A T I O N
54c53,54
< as strings are inserted in the new table.
---
> as strings are inserted in the new table.  Pruning should run in time linear   |
> in the number of codes in the old string table.                                |
63c63,64
< source files for encode/decode (including a Makefile) as assignment 4.
---
> source files for encode/decode (including a Makefile) as assignment 4.  Your   |
> Makefile should create encode and decode as hard links to the same inode.      |
107a108,111
>    As discussed in class, encode and becode may use separate data structures   |
>    (i.e., encode uses hashing with chaining and decode uses an array) or they  |
>    can both use a single, combined data structure.                             |
> 
115c119,120
<    all existing codes).
---
>    all existing codes).  If the table is pruned, the number of strings is      |
>    reduced and the number of chains may need to be reduced accordingly.        |
123,124c128,129
<    2) Do you need separate arrays of structs for the (PREF,CHAR) pairs and the
<       hash nodes?
---
>    2) How many copies of the (PREF,CHAR) pairs do you need to store?  How many |
>       copies do you need when doubling the size of the table?  When pruning?   |
128c133,137
<    4) Implement encode and decode without worrying about how much storage you
---
>    4) Which of the following variables (A or B) requires less space?           |
>       struct {int a; char b;} A[100];                                        |
>       struct {int a[100]; char b[100];} B;                                   |
> 
>    5) Implement encode and decode without worrying about how much storage you
143,144c152,154
<      setvbuf (stdin,  bin,  _IONBF, 0);
<      setvbuf (stdout, bout, _IONBF, 0);
---
>      static char bin[64], bout[64];             // Use small static buffers    |
>      setvbuf (stdin,  bin,  _IOFBF, 64);                                       |
>      setvbuf (stdout, bout, _IOFBF, 64);                                       |
179c189,198
<    be free()-ed before exiting, it must all be reachable at that time.
---
>    be free()-ed before exiting, it must all be reachable at that time; i.e.,   |
>    valgrind should report 0 bytes lost.                                        |
> 
>    Note:  When main() returns, storage for all variables stored on the stack   |
>    is freed before valgrind checks for unreachable heap storage.  Thus if an   |
>    argument or automatic local variable contained the only pointer to a block  |
>    on the heap, valgrind will report that block as being unreachable.  One     |
>    solution is to call exit() instead of returning, so that stack storage is   |
>    not freed.  Another is to store the pointer in a global or static local     |
>    variable (which is not stored on the stack).                                |
208c227
<    * (20 points) implementing the -m option
---
>    * (30 points) implementing the -m option
221a242,245
>      Here the number of bytes includes all storage in the data (= global and   |
>      static local variables), heap (= malloc()-ed), and stack (= arguments and |
>      automatic local variables) segments and the limits apply att all times.   |
> 
308,310c332,334
< H. When the -p WINDOW option creates a new table, it might not assign the same
<    code to a string; that is, the old code may no longer be valid either for
<    sending or as a prefix.
---
> H. When the -p option creates a new table, it might not assign the same code to|
>    a string; that is, the old code may no longer be valid either for sending or|
>    as a prefix.                                                                |
404c428
<                                                               CS-323-10/22/20
---
>                                                               CS-323-11/03/20|