reverse-string.py

# Time: O(n)
# Space: O(n)

# Write a function that takes a string as input and
# returns the string reversed.
#
# Example:
# Given s = "hello", return "olleh".

class Solution(object):
 def reverseString(self, s):
 """
 :type s: str
 :rtype: str
 """
 string = list(s)
 i, j = 0, len(string) - 1
 while i < j:
 string[i], string[j] = string[j], string[i]
 i += 1
 j -= 1
 return "".join(string)


# Time: O(n)
# Space: O(n)
class Solution2(object):
 def reverseString(self, s):
 """
 :type s: str
 :rtype: str
 """
 return s[::-1]