(7 kyu) Reverse words.java

// 1 Plain solution
import java.*;

public class Kata {
  public static String reverseWords(final String original) {
    String[] array = original.split(" ");
    if (arr.length == 0) {
      return original;
    }
    
    List<String> res = new ArrayList<String>();
    for (String w : array) {
      StringBuilder r = new StringBuilder();
      r.append(w);
      r = r.reverse();
      res.add(r.toString());
    }
    
    return String.join(" ", res);
  }
}

// 2 Optimized solution
import java.lang.StringBuilder;

public class Kata {
  public static String reverseWords(final String original) { 
    String[] array = original.split(" ");
    if (array.length == 0)
        return original;
    
    int i = 0;
    for(String string : array){
        array[i] = new StringBuilder(string).reverse().toString();
        i++;
    }
    
    return String.join(" ", array);
  }
}

// 3 Clever solution
import java.util.Arrays;
import java.util.stream.Collectors;

public class Kata {
  public static String reverseWords(final String original) {
    return Arrays.stream(original.split("(?<=\\s)|(?=\\s+)"))
                .map(str -> new StringBuilder(str).reverse().toString())
                .collect(Collectors.joining());
  }
}