upd

algorithms/labs/lab6/leetcode/1/link.txt

@@ -0,0 +1 @@
+https://leetcode.com/problems/regular-expression-matching/submissions/1769086671/?envType=problem-list-v2&envId=dynamic-programming

algorithms/labs/lab6/leetcode/1/solution.py

@@ -0,0 +1,14 @@
+class Solution:
+    def isMatch(self, s: str, p: str) -> bool:
+        from functools import lru_cache
+
+        @lru_cache(None)
+        def dp(i: int, j: int) -> bool:
+            if j == len(p):
+                return i == len(s)
+            first = i < len(s) and (p[j] == s[i] or p[j] == ".")
+            if j + 1 < len(p) and p[j + 1] == "*":
+                return dp(i, j + 2) or (first and dp(i + 1, j))
+            return first and dp(i + 1, j + 1)
+
+        return dp(0, 0)

algorithms/labs/lab6/leetcode/2/link.txt

@@ -0,0 +1 @@
+https://leetcode.com/problems/longest-valid-parentheses/submissions/1769090768/?envType=problem-list-v2&envId=dynamic-programming

algorithms/labs/lab6/leetcode/2/solution.py

@@ -0,0 +1,15 @@
+class Solution:
+    def longestValidParentheses(self, s: str) -> int:
+        n = len(s)
+        dp = [0] * n
+        best = 0
+        for i in range(1, n):
+            if s[i] == ")":
+                if s[i - 1] == "(":
+                    dp[i] = (dp[i - 2] if i >= 2 else 0) + 2
+                elif i - dp[i - 1] - 1 >= 0 and s[i - dp[i - 1] - 1] == "(":
+                    dp[i] = dp[i - 1] + 2
+                    if i - dp[i - 1] - 2 >= 0:
+                        dp[i] += dp[i - dp[i - 1] - 2]
+                best = max(best, dp[i])
+        return best

algorithms/labs/lab6/leetcode/3/link.txt

@@ -0,0 +1 @@
+https://leetcode.com/problems/trapping-rain-water/?envType=problem-list-v2&envId=dynamic-programming

algorithms/labs/lab6/leetcode/3/solution.py

@@ -0,0 +1,20 @@
+from typing import List
+
+
+class Solution:
+    def trap(self, height: List[int]) -> int:
+        n = len(height)
+        if n == 0:
+            return 0
+        left = [0] * n
+        right = [0] * n
+        left[0] = height[0]
+        for i in range(1, n):
+            left[i] = max(left[i - 1], height[i])
+        right[-1] = height[-1]
+        for i in range(n - 2, -1, -1):
+            right[i] = max(right[i + 1], height[i])
+        ans = 0
+        for i in range(n):
+            ans += min(left[i], right[i]) - height[i]
+        return ans