Maximum Number of Removable Characters

lcpy gen -n 1898   # by problem number
lcpy gen -s maximum_number_of_removable_characters   # by problem name

Input: s = "abcacb", p = "ab", removable = [3,1,0]
Output: 2

Input: s = "abcbddddd", p = "abcd", removable = [3,2,1,4,5,6]
Output: 1

Input: s = "abcab", p = "abc", removable = [0,1,2,3,4]
Output: 0

class Solution:
    # Time: O(len(s) * log(len(removable)))
    # Space: O(len(removable))
    def maximum_removals(self, s: str, p: str, removable: list[int]) -> int:
        def is_subsequence(removed: set[int]) -> bool:
            i = 0
            for j, ch in enumerate(s):
                if i == len(p):
                    return True
                if j in removed or ch != p[i]:
                    continue
                i += 1
            return i == len(p)

        lo, hi = 0, len(removable)
        while lo < hi:
            mid = (lo + hi + 1) // 2
            if is_subsequence(set(removable[:mid])):
                lo = mid
            else:
                hi = mid - 1
        return lo