# 1209-remove-all-adjacent-duplicates-in-string-ii Try it on leetcode ## Description

You are given a string s and an integer k, a k duplicate removal consists of choosing k adjacent and equal letters from s and removing them, causing the left and the right side of the deleted substring to concatenate together.

We repeatedly make k duplicate removals on s until we no longer can.

Return the final string after all such duplicate removals have been made. It is guaranteed that the answer is unique.

 

Example 1:

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

Example 2:

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"

Example 3:

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

 

Constraints:

## Solution(Python) ```Python class Solution: def removeDuplicates(self, s: str, k: int) -> str: stack = [] for c in s: if stack and c == stack[-1][0]: stack[-1][1] += 1 else: stack.append([c, 1]) if stack[-1][1] == k: stack.pop() return "".join(i * j for i, j in stack) ```