mirror of
https://github.com/autistic-symposium/master-algorithms-py.git
synced 2025-04-30 12:46:11 -04:00
66 lines
1.4 KiB
Python
Executable File
66 lines
1.4 KiB
Python
Executable File
#!/usr/bin/env python
|
|
|
|
__author__ = "bt3"
|
|
|
|
|
|
'''
|
|
Implement a trie. (Write the API and code for inserting into a trie).
|
|
'''
|
|
|
|
def make_trie(*args):
|
|
trie = {}
|
|
|
|
for word in args:
|
|
temp_trie = trie
|
|
for letter in word:
|
|
temp_trie = temp_trie.setdefault(letter, {})
|
|
temp_trie = temp_trie.setdefault('_end_', '_end_')
|
|
|
|
return trie
|
|
|
|
|
|
def in_trie(trie, word):
|
|
temp_trie = trie
|
|
for letter in word:
|
|
if letter not in temp_trie:
|
|
return False
|
|
temp_trie = temp_trie[letter]
|
|
return True
|
|
|
|
|
|
def remove_from_trie(trie, word, depth):
|
|
if word and word[depth] not in trie:
|
|
return False
|
|
|
|
if len(word) == depth + 1:
|
|
del trie[word[depth]]
|
|
if not trie:
|
|
return True
|
|
return False
|
|
else:
|
|
temp_trie = trie
|
|
|
|
if remove_from_trie(temp_trie[word[depth]], word, depth + 1):
|
|
if temp_trie:
|
|
del temp_trie[word[depth]]
|
|
return not temp_trie
|
|
return False
|
|
|
|
|
|
if __name__ == '__main__':
|
|
trie = make_trie('hello', 'abc', 'baz', 'bar', 'barz')
|
|
print 'This is the trie:'
|
|
print trie
|
|
|
|
assert(in_trie(trie, 'hello') == True)
|
|
assert(in_trie(trie, 'bar') == True)
|
|
assert(in_trie(trie, 'bab') == False)
|
|
assert(in_trie(trie, 'zzz') == False)
|
|
|
|
remove_from_trie(trie, 'abc', 0)
|
|
assert(in_trie(trie, 'abc') == False)
|
|
|
|
|
|
|
|
|