trie

Implement T9 Dictionary using Trie?

[亡魂溺海] 提交于 2019-12-06 15:42:19
I have to implement the T9 Dictionary . Essentially, when I am pressing any of the 9 keys, it should show me the top 5 words that can be started with that combination of keys. If I type '46', it can give 'hotel' or 'good' depending on whether I intended 'g' or 'h' when I pressed 4. The priority is based on which words are relatively popular - you can use, say, the first 5000 words from the top 100 000 words. The code I am doing is: Import import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.util.Date; import java.util.HashMap; import java.util.LinkedList;

What does radix mean in a radix tree?

杀马特。学长 韩版系。学妹 提交于 2019-12-05 19:20:34
I was trying to understand the radix tree (or compact prefix tree) data structure . I understand how lookup, insert and delete works with it. But I could not understand what does radix mean in a radix tree. What is the purpose of radix here? As already mentioned by @ta in the Wikipedia etymology link , the 'radix', is the the base of your trie. In this case we mean the numeric base, and we'll consider storing binary data. Radix R = 2 ^ x, where x >= 1. Take the example of a binary (2-ary) trie. The radix is 2, so at each node you can compare one bit . The two children will handle all of the

O(1) algorithm to determine if node is descendant of another node in a multiway tree?

北战南征 提交于 2019-12-05 17:20:05
问题 Imagine the following tree: A / \ B C / \ \ D E F I'm looking for a way to query if for example F is a descendant of A (note: F doesn't need to be a direct descendant of A), which, in this particular case would be true. Only a limited amount of potential parent nodes need to be tested against a larger potential descendants node pool. When testing whether a node is a descendant of a node in the potential parent pool, it needs to be tested against ALL potential parent nodes. This is what a came

Why is my Trie lookup slower than that of the standard F# Map's?

倖福魔咒の 提交于 2019-12-05 13:30:26
So, I just ported the Trie from OCaml. Unfortunately, it runs slower than the standard Map in terms of tryFind. I don't understand this - the trie seems like it should be faster. Is F#'s code libraries built in some special way as to make them faster than the code that the user typically deploys? Here's the code - [<RequireQualifiedAccess>] module Trie type Node<'k, 'v when 'k : comparison> = { TrieMap : Map<'k, Node<'k, 'v>> TrieKvp : ('k list * 'v) option } member inline x.IsEmpty = x.TrieKvp.IsNone && x.TrieMap.IsEmpty let inline make map kvp = { TrieMap = map TrieKvp = kvp } let inline

Prefix vs Suffix Trie in String Matching

独自空忆成欢 提交于 2019-12-05 11:47:30
I'm not too well-versed about the actual algorithms used in string matching with tries. I'm wondering why there seems to be more focus on suffix tries for string matching rather than prefix tries. Can we not use prefix tries for substring matching also? Put in another way, what are the advantages of suffix tries over prefix tries? .retteb era seirt xiferp ,drawkcab daer uoy fI Seriously. Suffix tries allow you to traverse from the beginning of a string. 来源: https://stackoverflow.com/questions/6692441/prefix-vs-suffix-trie-in-string-matching

Erlang: What is most-wrong with this trie implementation?

左心房为你撑大大i 提交于 2019-12-05 09:57:54
Over the holidays, my family loves to play Boggle. Problem is, I'm terrible at Boggle. So I did what any good programmer would do: wrote a program to play for me. At the core of the algorithm is a simple prefix trie , where each node is a dict of references to the next letters. This is the trie:add implementation: add([], Trie) -> dict:store(stop, true, Trie); add([Ch|Rest], Trie) -> % setdefault(Key, Default, Dict) -> % case dict:find(Key, Dict) of % { ok, Val } -> { Dict, Val } % error -> { dict:new(), Default } % end. { NewTrie, SubTrie } = setdefault(Ch, dict:new(), Trie), NewSubTrie = add

How can I store data in a table as a trie? (SQL Server)

為{幸葍}努か 提交于 2019-12-05 02:15:31
问题 To make things easier, the table contains all the words in the English dictionary. What I would like to do is be able to store the data as a trie. This way I can traverse the different branches of the trie and return the most relevant result. First, how do I store the data in the table as a trie? Second, how do I traverse the tree? If it helps at all, the suggestion in this previous question is where this question was sparked from. Please make sure it's SQL we're talking about. I understood

Is there any way I can speed up this VBA algorithm?

不羁的心 提交于 2019-12-05 01:14:21
I am looking to implement a VBA trie -building algorithm that is able to process a substantial English lexicon (~50,000 words) in a relatively short amount of time (less than 15-20 seconds). Since I am a C++ programmer by practice (and this is my first time doing any substantial VBA work), I built a quick proof-of-concept program that was able to complete the task on my computer in about half a second. When it came time to test the VBA port however, it took almost two minutes to do the same -- an unacceptably long amount of time for my purposes. The VBA code is below: Node Class Module: Public

Search a string as you type the character

非 Y 不嫁゛ 提交于 2019-12-04 18:21:03
问题 I have contacts stored in my mobile. Lets say my contacts are Ram Hello Hi Feat Eat At When I type letter 'A' I should get all the matching contacts say "Ram, Feat, Eat, At" . Now I type one more letter T . Now my total string is "AT" now my program should reuse the results of previous search for "A" . Now it should return me "Feat, Eat, At" Design and develop a program for this. This is interview question at Samsung mobile development I tried solving with Trie data structures . Could not get

How do you store a trie in a relational database?

若如初见. 提交于 2019-12-04 16:24:12
问题 I have a prefix trie. What is the recommended schema for representing this structure in a relational database? I need substring matching to remain efficient. 回答1: How about the Materialized Path design? CREATE TABLE trie ( path VARCHAR(<maxdepth>) PRIMARY KEY, ...other attributes of a tree node... ); To store a word like "stackoverflow": INSERT INTO trie (path) VALUES ('s'), ('st'), ('sta'), ('stac'), ('stack'), ('stacko'), ('stackov'), ('stackove'), ('stackover'), ('stackover'), ('stackoverf