151_Reverse_words_in_string

// https://leetcode.com/problems/reverse-words-in-a-string/

// MY approach

class Solution {
    public String reverseWords(String s) {
        if (s.length() == 0 || s.equals("") || s.equals(" "))
            return "";
        StringBuffer sb = new StringBuffer();
        int i = 0;
        String tmp = "";
        
        int f = 0;
        while(i < s.length()) {
            while (i<s.length() && s.charAt(i)!=' ') {
                tmp += s.charAt(i);
                f = 1;
                i++;
            }
            if (f == 1) {
                sb.insert(0,tmp+" ");
                tmp = "";    
                f = 0;
            }
            i++;
        }

        if (sb.length() > 0) {
            while (sb.charAt(sb.length()-1)==' ')
                sb.deleteCharAt(sb.length()-1);    
        }
        
        return sb.toString();
        
    }
}

// best

String[] parts = s.trim().split("\\s+");
String out = "";
for (int i = parts.length - 1; i > 0; i--) {
    out += parts[i] + " ";
}
return out + parts[0];