lt-reverse-word.cpp

class Solution {
public:
    string reverseWords(string s) {
        int n = s.size();
        int wordStart = 0;
        for(int i = 0; i < n; i++){
            // if current char is a space
            if(s.at(i) == ' ') {
                string reversed = reverseString(s.substr(wordStart, i - wordStart));
                s.replace(wordStart, i - wordStart, reversed);
                wordStart = i + 1;
            } else if(i == n - 1) {
                string reversed = reverseString(s.substr(wordStart, i - wordStart + 1));
                s.replace(wordStart, i - wordStart + 1, reversed);
            };

        }
        return s;
    }
    
    string reverseString(string s) {
        int n = s.size() - 1;
        for(int i = 0; i <= n / 2; i++) {
            char t = s[n - i];
            s[n - i] = s[i];
            s[i] = t;
        }
        return s;
    }
};