hashtable

问题 There is one thing about linear probing (hash tables) that is not intuitive to me. If I put key1 which hash results to array index 1. Then I put key2 -> array index 2. Then I put key3 -> again array index 1, this will go to array index 3. Then when I search for key3 I should go through indexes that contain keys that do not have the same hash as mine at all. Isn't this waste? If the sequence is really big and contains many keys (for example I have 20 elements, then null, for any key that

问题 Ok, so I've been doing some experiments with hash tables and different collision resolution problems. I'm trying to figure out which is more efficient for doing finds, a hash table that uses separate chaining or quadratic probing for collision resolution. My results suggest that separate chaining is faster than quadratic probing even for small load factors such as 0.4 or 0.2. Is this the case or are my results wrong? 回答1: The difference in processing cost between the two approaches are that

问题 In .NET you can select a hashtable as type for a usersetting. However when I save it and retrieve it in this way, it doesnt seem to have saved it at all. Hashtable t = new Hashtable(); t.Add(1,"Foo"); t.Add(2,"Bar"); Properties.Settings.Default.Setting = t; Properties.Settings.Default.Save(); if(Properties.Settings.Default.Setting != null) foreach (DictionaryEntry entry in Properties.Settings.Default.Setting) { MessageBox.Show(entry.Key + " " + entry.Value); } Why doesnt it serialize it in

问题 I would like to build pandas from source rather than use a package manager because I am interested in contributing. The first time I tried to build pandas, these were the steps I took: 1) created the virtualenv mkvirtualenv --no-site-packages pandas 2) activated the virtualenv 3) installed Anaconda CE. However, this was installed in ~/anaconda. 4) cloned pandas 5) built C extensions in place (pandas)ems ~/.virtualenvs/pandas/localrepo/pandas> ~/anaconda/bin/python setup.py build_ext --inplace

问题 I am looking for an open source C implementation of a hash table that keeps all the data in one memory block, so it can be easily send over a network let say. I can only find ones that allocate small pieces of memory for every key-value pair added to it. Thank you very much in advance for all the inputs. EDIT: It doesn't necessarily need to be a hash table, whatever key-value pair table would probably do. 回答1: On a unix system I'd probably utilise a shared memory buffer (see shm_open()), or

问题 I am looking for an open source C implementation of a hash table that keeps all the data in one memory block, so it can be easily send over a network let say. I can only find ones that allocate small pieces of memory for every key-value pair added to it. Thank you very much in advance for all the inputs. EDIT: It doesn't necessarily need to be a hash table, whatever key-value pair table would probably do. 回答1: On a unix system I'd probably utilise a shared memory buffer (see shm_open()), or

问题 Do you know a good and free Hashtable imlementation for Delphi 5 ? I need to organize a huge amount of data in a hastable and I am bit worried about memory leak issues that I found in most available implementations on the web. Tks 回答1: You can also check out the open-source / formerly commercial TurboPower SysTools. Not sure how much it is being updated. At one point Julian Bucknall recommended it over his EZDSL library, although that was back when he still worked fur TurboPower and it was

问题 Can someone please explain Why my first examples don't work, and why adding in a ForEach-Object solves the problem? Thanks in advance! I parsed the return from a command into a hashtable (sample at end of post) and want to log the information to a file as part of my processing. I know that $ht.GetEnumerator() | Sort-Object Name will return the full hash to screen, sorted. However, once I try sending things to file, it breaks. $ht | Add-Content log.txt only logs a single row of System

问题 My current script will take an expression, ex: my $expression = '( a || b || c )'; and go through each boolean combination of inputs using sub/replace, like so: my $keys = join '|', keys %stimhash; $expression =~ s/($keys)\b/$stimhash{$1}/g; So for example expression may hold, ( 0 || 1 || 0 ) This works great. However, I would like to allow the variables (also in %stimhash) to contain a tag, *. my $expression = '( a* || b* || c* )'; Also, printing the keys of the stimhash returns: a*|b*|c* It

问题 My current script will take an expression, ex: my $expression = '( a || b || c )'; and go through each boolean combination of inputs using sub/replace, like so: my $keys = join '|', keys %stimhash; $expression =~ s/($keys)\b/$stimhash{$1}/g; So for example expression may hold, ( 0 || 1 || 0 ) This works great. However, I would like to allow the variables (also in %stimhash) to contain a tag, *. my $expression = '( a* || b* || c* )'; Also, printing the keys of the stimhash returns: a*|b*|c* It