Create 10. Maximum Number of Removable Characters.py

11_Binary-Search/10. Maximum Number of Removable Characters.py

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+# https://leetcode.com/problems/maximum-number-of-removable-characters/
+
+class Solution:
+    def maximumRemovals(self, s: str, p: str, removable: List[int]) -> int:
+        def isSubsequence(mid):
+            remove = set(removable[:mid+1])
+            i = j = 0
+            while i < len(s) and j < len(p):
+                if s[i] == p[j] and i not in remove:
+                    j += 1
+                i += 1
+            return j == len(p)
+
+
+        res = 0
+        l, r = 0, len(removable)-1
+        while l <= r:
+            mid = l + (r - l)//2
+            if isSubsequence(mid):
+                res = max(res, mid+1)
+                l = mid + 1
+            else:
+                r = mid - 1
+
+        return res
+
+
+# Time: (n * log(k))   # n = len(s), k = len(removable)