Written by Ron on 010111 April 000112011. Posted in Blog

Given an input string s, reverse the order of the words.

A word is defined as a sequence of non-space characters. The words in s will be separated by at least one space.

Return a string of the words in reverse order concatenated by a single space.

Note that s may contain leading or trailing spaces or multiple spaces between two words. The returned string should only have a single space separating the words. Do not include any extra spaces.

Example 1:
Input: s = "the sky is blue"
Output: "blue is sky the"

Example 2:
Input: s = "  hello world  "
Output: "world hello"
Explanation: Your reversed string should not contain leading or trailing spaces.

Example 3:
Input: s = "a good   example"
Output: "example good a"
Explanation: You need to reduce multiple spaces between two words to a single space in the reversed string.

class Solution:
    def reverseWords(self, s: str) -> str:
        return " ".join(s.split()[::-1])
    
    def reverseWords(self, s: str) -> str:
        return " ".join(reversed(s.split()))
    
    def reverseWords(self, s: str) -> str:
        return " ".join(reversed(list(filter(None, s.split(" ")))))
        
s = Solution()

print(s.reverseWords("the sky is blue"))#"blue is sky the"
print(s.reverseWords("  hello world  "))#"world hello"
print(s.reverseWords("a good   example"))#"example good a"