Remove All Adjacent Duplicates in String II

lcpy gen -n 1209   # by problem number
lcpy gen -s remove_all_adjacent_duplicates_in_string_ii   # by problem name

Input: s = "abcd", k = 2
Output: "abcd"
Explanation: There's nothing to delete.

Input: s = "deeedbbcccbdaa", k = 3
Output: "aa"
Explanation: First delete "eee" and "ccc", get "ddbbbdaa"
Then delete "bbb", get "dddaa"
Finally delete "ddd", get "aa"

Input: s = "pbbcggttciiippooaais", k = 2
Output: "ps"

class Solution:
    # Time: O(len(s))
    # Space: O(len(s))
    def remove_duplicates(self, s: str, k: int) -> str:
        stack: list[tuple[str, int]] = []
        for char in s:
            if stack and stack[-1][0] == char:
                char, count = stack[-1]
                if count + 1 == k:
                    stack.pop()
                else:
                    stack[-1] = (char, count + 1)
            else:
                stack.append((char, 1))
        return "".join(char * count for char, count in stack)