344 Reverse string

Original Description: Write a function that takes a string as input and returns the string reversed.

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• 要求： 将一个给定string reverse

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• 返回： reverse后的string

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• 例子：
  • input: ‘hello’
  • output: ‘olleh’

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Solution

以string的中间位置为pivot，将其左右两边character进行交换。 Note: 中间位置 = \(len(s)//2\)

class Solution(object):
    def reverseString(self, s):
        """
        :type s: str
        :rtype: str
        """
        l = [ss for ss in s]
        for i in range(len(l)//2):
            tmp = l[i]
            l[i] = l[-(i+1)]
            l[-(i+1)] = tmp
        return "".join(l)