Reverse Words in a String
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.
Follow-up: If the string data type is mutable in your language, can you solve it in-place with O(1) extra space?
Example 1
Input
s = "the sky is blue"Output
"blue is sky the"The words are reversed and joined by a single space.
Example 2
Input
s = " hello world "Output
"world hello"Your reversed string should not contain leading or trailing spaces.
Constraints
- 1 <= s.length <= 10^4
- s contains English letters (upper-case and lower-case), digits, and spaces ' '.
- There is at least one word in s.
Asked at 29 companies
Practice questions like this out loud in a mock coding interview with a live AI interviewer. First one free.