Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Auto-complete feature using Trie
We have a Trie, and when a user enters a character, we have to show the matching string the Trie. This feature we call it as auto-completion. For example, if a Trie contains "xyzzzz,""xyz," "xxxyyxzzz" and when the user enter xy, then we have to show them xyzzzz, xyz, etc..,
Steps to achieve the result.
Search for the string using the standard Trie algorithm.
If the string is not present, then return -1.
If the string is present and is the end of a word in Trie, then print the string.
If the matching string doesn't have any node, then return.
Else print all the nodes.
Let's start coding.
# class for Trie Node
class TrieNode():
def __init__(self):
# initialising trie node
self.trie_node = {}
self.last_node = False
class Trie():
def __init__(self):
# initialising the trie
self.root = TrieNode()
# list to store the words
self.words = []
def create_trie(self, keys):
# creating the Trie using data
for key in keys:
# inserting one key to the trie
self.insert_node(key)
def insert_node(self, key):
node = self.root
for obj in list(key):
if not node.trie_node.get(obj):
# creating a TrieNode
node.trie_node[obj] = TrieNode()
node = node.trie_node[obj]
# making leaf node
node.last_node = True
def search(self, key):
# searching for the key
node = self.root
is_found = True
for obj in list(key):
if not node.trie_node.get(obj):
is_found = False
break
node = node.trie_node[obj]
return node and node.last_node and is_found
def matches(self, node, word):
if node.last_node:
self.words.append(word)
for obj, n in node.trie_node.items():
self.matches(n, word + obj)
def show_auto_completion(self, key):
node = self.root
is_found = False
temp = ''
for obj in list(key):
# checking the word
if not node.trie_node.get(obj):
is_found = True
break
temp += obj
node = node.trie_node[obj]
if is_found:
return 0
elif node.last_node and not node.trie_node:
return -1
self.matches(node, temp)
for string in self.words:
print(string)
return 1
# data for the Trie
strings = ["xyz", "xyzzzz", "xyabad", "xyyy", "abc", "abbccc", "xyx", "xyxer",
a"]
# word for auto completion
string = "xy"
status = ["Not found", "Found"]
# instantiating Trie class
trie = Trie()
# creating Trie using the strings
trie.create_trie(strings)
# getting the auto completion words for the string from strings
result = trie.show_auto_completion(string)
if result == -1 or result == 0:
print("No matches")If you run the above code, you will get the following result.
xyz xyzzzz xyabad xyyy xyx xyxer
Updated on: 21-Sep-2020
399 Views
Advertisements