(LEETCODE)Regular _Expression_ Matching.py

Author: yashaswinipai

Dynamic Programming/(LEETCODE)Regular _Expression_ Matching.py

@@ -0,0 +1,22 @@
+// Solution to https://leetcode.com/problems/regular-expression-matching
+  
+  class Solution:
+    def isMatch(self, s: str, p: str) -> bool:
+        cache={}
+        def dfs(i,j):
+            if (i,j) in cache:
+                return cache[(i,j)]
+            if i>=len(s) and j>=len(p):
+                return True
+            if j>=len(p):
+                return False
+            match=i<len(s) and(s[i]==p[j] or p[j]==".")
+            if (j+1)<len(p) and p[j+1]=="*":
+                cache[(i,j)]=(dfs(i,j+2) or (match and dfs(i+1,j)))
+                return  cache[(i,j)]
+            if match:
+                cache[(i,j)]=dfs(i+1,j+1)
+                return  cache[(i,j)]
+            cache[(i,j)]=False
+            return False
+        return dfs(0,0)