- 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来存储处理过的字符，如果li最后一个元素与遍历的元素一样，删除li最后一个元素，否则li+=
代码：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
