Reverse words in a String Leetcode Solution
In this tutorial, we will solve a leetcode problem, reverse words in a string in python.
Task:
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.
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.
Solution:
class Solution:
def reverseWords(self, s: str) -> str:
lst = s.split()
lst, s = lst[::-1], ""
for i in lst:
s += i
s += ' '
return s.strip()
Steps:
step1: First, In this problem, we split the string s and store it into a list last by using .split() function.
step2: Then, reverse the list last and re-declare the string s as empty.
step3: Now, loop through the list lst and add the element into string s with space.
step4: After the loop, we return the string s but also remove any unnecessary white spaces using the function .strip()
