update

Author: tiationg-kho

README.md

@@ -199,15 +199,15 @@ Pattern500 is inspired by Blind 75 and Grind 75's classic problem selection. Pat
 | 185 | | [6. Zigzag Conversion](https://leetcode.com/problems/zigzag-conversion/) | [F]string | string composition | [Python]([F]string/[F]string/6-zigzag-conversion.py) |
 | 186 | | [trie]([G]trie/trie.md) | [G]trie | | |
 | 187 | O | [208. Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/) | [G]trie | standard trie | [Python]([G]trie/[G]trie/208-implement-trie-prefix-tree.py) |
-| 188 | O | [XX]()   | [X]XX  | XX   | [Python]()  |
-| 189 | O | [XX]()  | [X]XX  | XX   | [Python]()  |
-| 190 | O | [XX]()   | [X]XX  | XX   | [Python]()  |
-| 191 | O | [XX]()   | [X]XX  | XX   | [Python]()  |
-| 192 | O | [XX]()   | [X]XX  | XX   | [Python]()  |
-| 193 | O | [XX]()  | [X]XX  | XX   | [Python]()  |
-| 194 | O | [XX]()   | [X]XX  | XX   | [Python]()  |
-| 195 | O | [XX]()  | [X]XX  | XX   | [Python]()  |
-| 196 | O | [XX]()   | [X]XX  | XX   | [Python]()  |
+| 188 | O | [588. Design In-Memory File System](https://leetcode.com/problems/design-in-memory-file-system/) | [G]trie | custom trie node | [Python]([G]trie/[G]trie/588-design-in-memory-file-system.py) |
+| 189 |  | [1268. Search Suggestions System](https://leetcode.com/problems/search-suggestions-system/) | [G]trie | custom trie node | [Python]([G]trie/[G]trie/1268-search-suggestions-system.py) |
+| 190 |  | [2185. Counting Words With a Given Prefix](https://leetcode.com/problems/counting-words-with-a-given-prefix/) | [G]trie | custom trie node | [Python]([G]trie/[G]trie/2185-counting-words-with-a-given-prefix.py) |
+| 191 |  | [2416. Sum of Prefix Scores of Strings](https://leetcode.com/problems/sum-of-prefix-scores-of-strings/) | [G]trie | custom trie node | [Python]([G]trie/[G]trie/2416-sum-of-prefix-scores-of-strings.py) |
+| 192 |  | [745. Prefix and Suffix Search](https://leetcode.com/problems/prefix-and-suffix-search/) | [G]trie | custom trie node | [Python]([G]trie/[G]trie/745-prefix-and-suffix-search.py) |
+| 193 |  | [1166. Design File System](https://leetcode.com/problems/design-file-system/) | [G]trie | custom trie node | [Python]([G]trie/[G]trie/1166-design-file-system.py) |
+| 194 | O | [211. Design Add and Search Words Data Structure](https://leetcode.com/problems/design-add-and-search-words-data-structure/) | [G]trie | perform dfs inside trie | [Python]([G]trie/[G]trie/211-design-add-and-search-words-data-structure.py) |
+| 195 |  | [472. Concatenated Words](https://leetcode.com/problems/concatenated-words/) | [G]trie | perform dfs inside trie | [Python]([G]trie/[G]trie/472-concatenated-words.py) |
+| 196 |  | [642. Design Search Autocomplete System](https://leetcode.com/problems/design-search-autocomplete-system/) | [G]trie | perform dfs inside trie | [Python]([G]trie/[G]trie/642-design-search-autocomplete-system.py) |
 | 197 | | [array]([H]array/array.md) | [H]array | | |
 | 198 | O | [XX]() | [X]XX | XX | [Python]() |
 | 199 | O | [XX]() | [X]XX | XX | [Python]() |

[G]trie/[G]trie/1166-design-file-system.py

@@ -0,0 +1,52 @@
+class TrieNode:
+ def __init__(self):
+ self.children = {}
+ self.val = - 1
+
+class Trie:
+ def __init__(self):
+ self.root = TrieNode()
+
+ def insert(self, path, val):
+ path = path.split('/')[1:]
+ node = self.root
+ for i, p in enumerate(path):
+ if p not in node.children:
+ if i == len(path) - 1:
+ node.children[p] = TrieNode()
+ else:
+ return False
+ node = node.children[p]
+ if node.val == - 1:
+ node.val = val
+ return True
+ else:
+ return False
+
+ def search(self, path):
+ path = path.split('/')[1:]
+ node = self.root
+ for p in path:
+ if p not in node.children:
+ return - 1
+ node = node.children[p]
+ return node.val
+
+class FileSystem:
+ def __init__(self):
+ self.trie = Trie()
+
+ def createPath(self, path: str, value: int) -> bool:
+ return self.trie.insert(path, value)
+
+ def get(self, path: str) -> int:
+ return self.trie.search(path)
+
+# Your FileSystem object will be instantiated and called as such:
+# obj = FileSystem()
+# param_1 = obj.createPath(path,value)
+# param_2 = obj.get(path)
+
+# time O(1) for init, O(L) for createPath() and get()
+# space O(nL)
+# using trie and custom trie node

[G]trie/[G]trie/1268-search-suggestions-system.py

@@ -0,0 +1,39 @@
+class TrieNode:
+ def __init__(self):
+ self.children = {}
+ self.suggests = []
+
+class Trie:
+ def __init__(self):
+ self.root = TrieNode()
+
+ def insert(self, s):
+ node = self.root
+ for c in s:
+ if c not in node.children:
+ node.children[c] = TrieNode()
+ node = node.children[c]
+ node.suggests.append(s)
+ node.suggests = sorted(node.suggests)[:3]
+ 
+ def search(self, s):
+ res = []
+ node = self.root
+ for i, c in enumerate(s):
+ if c not in node.children:
+ res.extend([[] for _ in range(len(s) - i)])
+ break
+ node = node.children[c]
+ res.append(node.suggests)
+ return res
+
+class Solution:
+ def suggestedProducts(self, products: List[str], searchWord: str) -> List[List[str]]:
+ trie = Trie()
+ for p in products:
+ trie.insert(p)
+ return trie.search(searchWord)
+
+# time O(nL)
+# space O(nL), nL nodes in trie, not counting suggests list storage in node
+# using trie and custom trie node and sort

[G]trie/[G]trie/208-implement-trie-prefix-tree.py

@@ -1,10 +1,9 @@
 class TrieNode:
  def __init__(self):
  self.children = {}
- self.isWord = False
+ self.is_word = False
 
 class Trie:
-
  def __init__(self):
  self.root = TrieNode()
 
@@ -14,15 +13,15 @@ def insert(self, word: str) -> None:
  if c not in node.children:
  node.children[c] = TrieNode()
  node = node.children[c]
- node.isWord = True
+ node.is_word = True
 
  def search(self, word: str) -> bool:
  node = self.root
  for c in word:
  if c not in node.children:
  return False
  node = node.children[c]
- return node.isWord
+ return node.is_word
 
  def startsWith(self, prefix: str) -> bool:
  node = self.root
@@ -31,7 +30,7 @@ def startsWith(self, prefix: str) -> bool:
  return False
  node = node.children[c]
  return True
- 
+
 # Your Trie object will be instantiated and called as such:
 # obj = Trie()
 # obj.insert(word)

[G]trie/[G]trie/211-design-add-and-search-words-data-structure.py

@@ -0,0 +1,54 @@
+class TrieNode:
+ def __init__(self):
+ self.children = {}
+ self.is_word = False
+
+class Trie:
+ def __init__(self):
+ self.root = TrieNode()
+ 
+ def insert(self, s):
+ node = self.root
+ for c in s:
+ if c not in node.children:
+ node.children[c] = TrieNode()
+ node = node.children[c]
+ node.is_word = True
+
+ def search(self, s):
+ return self.search_helper(s, self.root, 0)
+
+ def search_helper(self, s, node, idx):
+ for i in range(idx, len(s)):
+ if s[i] == '.':
+ for child in node.children.values():
+ if self.search_helper(s, child, i + 1):
+ return True
+ return False
+ if s[i] not in node.children:
+ return False
+ node = node.children[s[i]]
+ return node.is_word
+
+class WordDictionary:
+ def __init__(self):
+ self.trie = Trie()
+ self.len_set = set()
+
+ def addWord(self, word: str) -> None:
+ self.len_set.add(len(word))
+ self.trie.insert(word)
+
+ def search(self, word: str) -> bool:
+ if len(word) not in self.len_set:
+ return False
+ return self.trie.search(word)
+
+# Your WordDictionary object will be instantiated and called as such:
+# obj = WordDictionary()
+# obj.addWord(word)
+# param_2 = obj.search(word)
+
+# time O(nL or 26**L) for search(), O(L) for addWord()
+# space O(nL), n is the number of words, L is the max len
+# using trie and perform dfs inside trie and prune

[G]trie/[G]trie/2185-counting-words-with-a-given-prefix.py

@@ -0,0 +1,39 @@
+class TrieNode:
+ def __init__(self):
+ self.children = {}
+ self.count = 0
+
+class Trie:
+ def __init__(self):
+ self.root = TrieNode()
+
+ def insert(self, s):
+ node = self.root
+ for c in s:
+ if c not in node.children:
+ node.children[c] = TrieNode()
+ node = node.children[c]
+ node.count += 1
+ 
+ def search(self, s):
+ node = self.root
+ for c in s:
+ if c not in node.children:
+ return 0
+ node = node.children[c]
+ return node.count
+
+class Solution:
+ def prefixCount(self, words: List[str], pref: str) -> int:
+ trie = Trie()
+ for w in words:
+ trie.insert(w)
+ return trie.search(pref)
+
+# time O(nL)
+# space O(nL)
+# using trie and custom trie node
+'''
+1. using trie allows we change requested prefix frequently
+2. if prefix is fixed, and words are sorted. try binary search (O(klogn)))
+'''

[G]trie/[G]trie/2416-sum-of-prefix-scores-of-strings.py

@@ -0,0 +1,43 @@
+class TrieNode:
+ def __init__(self):
+ self.children = {}
+ self.count = 0
+ self.length = 0
+
+class Trie:
+ def __init__(self):
+ self.root = TrieNode()
+
+ def insert(self, s):
+ node = self.root
+ for i, c in enumerate(s):
+ if c not in node.children:
+ node.children[c] = TrieNode()
+ node = node.children[c]
+ node.count += 1
+ node.length = i + 1
+
+ def search(self, s):
+ res = 0
+ node = self.root
+ for c in s:
+ node = node.children[c]
+ res += node.count
+ if node.count == 1:
+ res += len(s) - node.length
+ break
+ return res
+
+class Solution:
+ def sumPrefixScores(self, words: List[str]) -> List[int]:
+ trie = Trie()
+ for w in words:
+ trie.insert(w)
+ res = []
+ for w in words:
+ res.append(trie.search(w))
+ return res
+ 
+# time O(nL)
+# space O(nL)
+# using trie and custom trie node and prune

[G]trie/[G]trie/472-concatenated-words.py

@@ -0,0 +1,50 @@
+class TrieNode:
+ def __init__(self):
+ self.children = {}
+ self.is_word = False
+
+class Trie:
+ def __init__(self):
+ self.root = TrieNode()
+ 
+ def insert(self, s):
+ node = self.root
+ for c in s:
+ if c not in node.children:
+ node.children[c] = TrieNode()
+ node = node.children[c]
+ node.is_word = True
+ 
+ def search(self, s):
+ return self.search_helper(s, self.root, 0)
+
+ def search_helper(self, s, node, idx):
+ for i in range(idx, len(s)):
+ if node.is_word:
+ if self.search_helper(s, self.root, i):
+ return True
+ if s[i] not in node.children:
+ return False
+ node = node.children[s[i]]
+ return node.is_word
+
+class Solution:
+ def findAllConcatenatedWordsInADict(self, words: List[str]) -> List[str]:
+ res = []
+ trie = Trie()
+ words.sort(key=len)
+ for w in words:
+ if trie.search(w):
+ res.append(w)
+ else:
+ trie.insert(w)
+ 
+ return res
+ 
+# time O(nlogn + nL + n * L**2), search is O(L**2) here not O(2**L), due to cost is L + L-1 + L-2 + ... + 1
+# space O(nL), n is the number of words, L is the max len
+# using trie and perform dfs inside trie and sort
+'''
+1. long word can only be consisted from short words, so we sort at first
+2. if certain word can be consisted from short words then no need to add in trie
+'''