lc1047. Remove All Adjacent Duplicates In String

1047. Remove All Adjacent Duplicates In String Easy

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Share Given a string S of lowercase letters, a duplicate removal consists of choosing two adjacent and equal letters, and removing them.

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

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

Example 1:

Input: "abbaca" Output: "ca" Explanation: For example, in "abbaca" we could remove "bb" since the letters are adjacent and equal, and this is the only possible move. The result of this move is that the string is "aaca", of which only "aa" is possible, so the final string is "ca".

Note:

1 <= S.length <= 20000 S consists only of English lowercase letters.

思路：用字符串li來存儲處理過的字符，若是li最後一個元素與遍歷的元素同樣，刪除li最後一個元素，不然li+=

代碼：python3

class Solution:
    def removeDuplicates(self, S: str) -> str:
        li=""
        for s in S:
            if li and li[-1]==s:
                li=li[:-1]
            else:
                li += s
        return li
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