Question:
Similar to Question [6. Reverse Words in a String], but with the following constraints:
“The input string does not contain leading or trailing spaces and the words are always separated by a single space.”
Could you do it in-place without allocating extra space?
class Solution(object):
def reverseWords(self, s):
"""
:type s: str
:rtype: str
"""
a = list(s)
left = 0
right = len(a) - 1
while left < right:
tmp = a[left]
a[left] = a[right]
a[right] = tmp
left += 1
right -= 1
left = 0
right = left
while right < len(a):
if a[right] == ' ':
ll = left
rr = right - 1
while ll < rr:
tmp = a[ll]
a[ll] = a[rr]
a[rr] = tmp
ll += 1
rr -= 1
left = right + 1
right += 1
return ''.join(a)
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