Reverse Words in a String

Problem Statement - link #

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.

Examples #

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.

Example 4:

Input: s = "  Bob    Loves  Alice   "
Output: "Alice Loves Bob"

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.

Solutions #

class Solution {
public:
    string reverseWords(string s) {
        
        string result="",word;
        stringstream ss(s);
        
        while(ss>>word)
            result = word + " " + result;
        
        result.pop_back();
        
        return result;
    }
};