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Reverse Words in a String

Problem Statement

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.

Leetcode link

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.

Constraints:

  • 1 <= s.length <= 104
  • s contains English letters (upper-case and lower-case), digits, and spaces ' '.
  • There is at least one word in s.

Code

Python Code
class Solution:
def reverseWords(self, s: str) -> str:
return " ".join(s.split()[::-1])

C++ Code
class Solution
{
public:
string reverseWords(string s)
{
stringstream ss(s);
string rev, w;

ss >> rev;
while (ss >> w) rev = w + " " + rev;

return rev.substr(0, rev.length());
}
};