151. Reverse Words in a String

class Solution {
public:
    string reverseWords(string s)
    {
        // Create a stringstream object to help with splitting the string
        // Clear the input string to reuse it for the result
        // Variable to store each word
        // Loop through each word separated by spaces in the stringstream
        while()
        {
            // Skip empty tokens (extra spaces)
            // If this is the first word added to the result string
                // Initialize the result string with the first word
                // For subsequent words
                // Prepend the word to the result string
        }
        // Return the result string with words reversed
    }
};

• Use >>

class Solution {
public:
    string reverseWords(string s)
    {
        stringstream ss(s);
        string token;
        s = "";
        while (ss >> token)
        {
            s = token + ' ' + s;
        }
        return s.substr(0, s.size() - 1);
    }
};

• T: $O(N)$

• S: $O(N)$

• Use >>

class Solution {
public:
    string reverseWords(string s)
    {
        stringstream ss(s);
        s = "";
        string token;
        while(is >> token)
        {
            s = (s.empty() ? token : token + " " + s);
        }
        return s;
    }
};

• T: $O(N)$

• S: $O(N)$

• Use getline

class Solution {
public:
    string reverseWords(string s)
    {
        stringstream ss(s);
        s = "";
        string token;
        while(getline(ss, token, ' '))
        {
            if(token.empty()) continue;
            if(s.empty())
            {
                s = token;
            }
            else
            {
                s = token + ' ' + s;
            }
        }
        return s;
    }
};

• T: $O(N)$
• S: $O(N)$