Prefix and Suffix Search

python/leetcode/Prefix and Suffix Search.py

@@ -0,0 +1,59 @@
+from typing import List
+from python.leetcode.libs.trie import TrieNode
+
+
+class WordFilter:
+
+    def __init__(self, words: List[str]):
+
+        self.prefix_root = TrieNode(key='', )
+        self.suffix_root = TrieNode(key='', )
+        self.prefix_cache = {}
+        self.suffix_cache = {}
+        self.answer_cache = {}
+
+        self.prefix_root.built_trie_by_words(words, self.prefix_cache)
+        self.suffix_root.built_trie_by_words([w[::-1]for w in words], self.suffix_cache)
+
+    def f(self, prefix: str, suffix: str) -> int:
+        key = (prefix, suffix)
+
+        if key in self.answer_cache:
+            return self.answer_cache[key]
+
+        node_with_prefix = self.prefix_cache.get(prefix, None)
+        node_with_suffix = self.suffix_cache.get(suffix[::-1], None)
+
+        if node_with_suffix == -1 or node_with_prefix == -1 or node_with_prefix is None or node_with_suffix is None:
+            return -1
+
+        common_indexes = node_with_prefix.values.intersection(node_with_suffix.values)
+        res = max(common_indexes)
+
+        self.answer_cache[key] = res
+        return self.answer_cache[key]
+
+
+if __name__ == "__main__":
+    obj = WordFilter(["apple", ])
+    assert obj.f('b', 'e') == -1
+
+    obj = WordFilter(["cabaabaaaa", "ccbcababac", "bacaabccba", "bcbbcbacaa", "abcaccbcaa", "accabaccaa",
+       "cabcbbbcca", "ababccabcb", "caccbbcbab", "bccbacbcba"])
+    assert obj.f('ab', 'abcaccbcaa') == 4
+    assert obj.f('ccbca', 'cbcababac') == 1
+    assert obj.f('bccbacbcba', 'a') == 9
+
+    assert obj.f('a', 'aa') == 5
+    assert obj.f('cabaaba', 'abaaaa') == 0
+    assert obj.f('cacc', 'accbbcbab') == 8
+    assert obj.f('ccbcab', 'bac') == 1
+    assert obj.f('bac', 'cba') == 2
+    assert obj.f('ac', 'accabaccaa') == 5
+    assert obj.f('bcbb', 'aa') == 3
+
+    obj = WordFilter(["apple", 'elephant', 'and', 'elent'])
+    assert obj.f('a', 'e') == 0
+
+    obj = WordFilter(["apple", 'elephant', 'and', 'elent', 'antre'])
+    assert obj.f('a', 'e') == 4

python/leetcode/power_of_two.py

@@ -0,0 +1,28 @@
+from math import log2, ceil, floor
+
+
+class Solution:
+    def isPowerOfTwo(self, n: int) -> bool:
+
+        if n <= 0:
+            return False
+
+        res = log2(n)
+
+        return ceil(res) == floor(res)
+
+
+if __name__ == "__main__":
+    obj = Solution()
+
+    assert obj.isPowerOfTwo(-16) is False
+
+    assert obj.isPowerOfTwo(8) is True
+
+    assert obj.isPowerOfTwo(1) is True
+
+    assert obj.isPowerOfTwo(2) is True
+
+    assert obj.isPowerOfTwo(3) is False
+
+    assert obj.isPowerOfTwo(16) is True