Merge pull request #104 from hg747/main

hgrosser: hash-list optimized, small improvements in parsing the file

Author: gcarreno

entries/hgrosser/README.md

@@ -3,19 +3,24 @@
 **1 billion row Challenge entry**
 
 ## Version
-Version 1.0
+Version 1.51
 
 ## How to compile
 The program was developed with FPC 3.2.2 and Lazarus 2.2.4
 
 ## How to start
 ```
-Usage:   hgrosser <path to input file> [buffer size in kb (Default=128 kb)]
-Example: hgrosser ./measurements.txt 128
+Usage:   <path to input file> <bit-width for hash-list (14..28)>
+Example: hgrosser measurements.txt 15
+ - bit-width for hash-list: sets the size of the hash list, e.g. '16' => 65536 entries
 ```
 There are no switches like `-i` etc, only values.
 
-Please start the program 3 times with buffer sizes of '128', '192' and '256'.
+### Optimizing the 2nd command line parameter
+
+In theory the program should run faster with greater bit-widths for the hash-list (because of less collisions), but on my own computer (8 GB RAM) in praxis a small value of 15 is the fastest way, allthough this causes many collisions.
+
+Please (if possible) try all values from 14 to 24 (maybe in a for-loop). Thanks a lot.
 
 ## How the program works
 The Program works with 1 thread.
@@ -24,5 +29,11 @@ To speed things up:
 
 - the input file is read via procedure 'blockread' ...
 - into an AnsiString, so that function 'PosEx' can be used to parse it
-- to manage the city names, a 'TFPHashList' is used
+- to manage the city names, a self made hash-list is used
 - temperatures are stored as integers (multiplied by 10)
+
+## History
+
+- Version 1.00: initial version
+- Version 1.50: hash-list optimized, small improvements in parsing the file
+- Version 1.51: small improvements in asm function