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Commit eef620d

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D. J.:
- Added the Bottom Up (Tabulation) DP Solution for the leetcode problem 10
1 parent 6d8c226 commit eef620d

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2 files changed

+52
-3
lines changed

2 files changed

+52
-3
lines changed

‎awesome_python_leetcode/_10_regular_expression_matching.py

Lines changed: 33 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,7 @@
11
class Solution:
22
"""Base class for all LeetCode Problems."""
33

4-
def isMatch(self, s: str, p: str) -> bool:
4+
def isMatchTD(self, s: str, p: str) -> bool:
55
"""
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Given an input string s and a pattern p, implement regular expression matching
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with support for '.' and '*' where:
@@ -10,6 +10,7 @@ def isMatch(self, s: str, p: str) -> bool:
1010
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The matching should cover the entire input string (not partial).
1212
"""
13+
# Top-Down Dynamic Programming (Memoization)
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# Time Complexity: O(n2)
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# Space Complexity: O(n2)
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dp = {}
@@ -32,3 +33,34 @@ def dfs(i: int, j: int) -> bool:
3233
return False
3334

3435
return dfs(0, 0)
36+
37+
def isMatchBU(self, s: str, p: str) -> bool:
38+
"""
39+
Given an input string s and a pattern p, implement regular expression matching
40+
with support for '.' and '*' where:
41+
- '.' Matches any single characters.
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- '*' Matches zero or more of the preceding element.
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The matching should cover the entire input string (not partial).
45+
"""
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# Bottom-Up Dynamic Programming (Tabulation)
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# Time Complexity: O(n2)
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# Space Complexity: O(n2)
49+
dp = [[False for _ in range(len(p) + 1)] for _ in range(len(s) + 1)]
50+
dp[0][0] = True
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52+
# Initialize first row
53+
for j in range(1, len(p) + 1):
54+
if p[j - 1] == "*":
55+
dp[0][j] = dp[0][j - 2]
56+
57+
# Fill the DP table
58+
for i in range(1, len(s) + 1):
59+
for j in range(1, len(p) + 1):
60+
if p[j - 1] == "." or p[j - 1] == s[i - 1]:
61+
dp[i][j] = dp[i - 1][j - 1]
62+
elif p[j - 1] == "*":
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dp[i][j] = dp[i][j - 2]
64+
if p[j - 2] == "." or p[j - 2] == s[i - 1]:
65+
dp[i][j] = dp[i][j] or dp[i - 1][j]
66+
return dp[-1][-1]

‎tests/test_10_regular_expression_matching.py

Lines changed: 19 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,24 @@
1414
("a", "ab*", True),
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],
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)
17-
def test_func(s: str, p: str, expected: bool):
17+
def test_funcTD(s: str, p: str, expected: bool):
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"""Tests the solution of a LeetCode problem."""
19-
is_match = Solution().isMatch(s, p)
19+
is_match = Solution().isMatchTD(s, p)
20+
assert is_match is expected
21+
22+
23+
@pytest.mark.parametrize(
24+
argnames=["s", "p", "expected"],
25+
argvalues=[
26+
("aa", "a", False),
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("aa", "a*", True),
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("ab", ".*", True),
29+
("aab", "c*a*b", True),
30+
("ab", ".*c", False),
31+
("a", "ab*", True),
32+
],
33+
)
34+
def test_funcBU(s: str, p: str, expected: bool):
35+
"""Tests the solution of a LeetCode problem."""
36+
is_match = Solution().isMatchBU(s, p)
2037
assert is_match is expected

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