/**
 * Created by forester on 08.11.15.
 */
public class Run {
    public static void main(String[] args) {
        String oneWord = "hello";
        String twoWordsSpace = "hello world";
        String twoWordsUnderscore = "hello_world";
        String allCases = "__  hello _ from demo    tests123  __  ";

        countWordLengths(oneWord);
        System.out.println();
        countWordLengths(twoWordsSpace);
        System.out.println();
        countWordLengths(twoWordsUnderscore);
        System.out.println();
        countWordLengths(allCases);
    }

    public static void countWordLengths(String str) {
        if (str.isEmpty())
            return;

        String word = "" + str.charAt(0);
        boolean prevCharIsSpace = isSpaceCharacter(str.charAt(0));
        int counter = prevCharIsSpace ? 0 : 1;

        for (int i = 1; i < str.length(); i++) {
            boolean curCharIsSpace = isSpaceCharacter(str.charAt(i));

            if (i == str.length() - 1) {
                counter = curCharIsSpace ? counter : counter + 1;
                word += curCharIsSpace ? "" : "" + str.charAt(i);

                if (counter != 0) {
                    System.out.println(word + ":" + counter);
                }
            }

            if (prevCharIsSpace && curCharIsSpace) {
                continue;
            } else if ((!prevCharIsSpace && !curCharIsSpace) || (curCharIsSpace && !prevCharIsSpace)) {
                if (!curCharIsSpace) {
                    counter++;
                    word += str.charAt(i);
                }

                prevCharIsSpace = curCharIsSpace;
            } else if ((!prevCharIsSpace && curCharIsSpace) || (!curCharIsSpace && prevCharIsSpace)) {
                if (counter != 0) {
                    System.out.println(word + ":" + counter);
                }

                counter = curCharIsSpace ? 0 : 1;
                word = curCharIsSpace ? "" : str.charAt(i) + "";
                prevCharIsSpace = curCharIsSpace;
            }
        }
    }

    public static boolean isSpaceCharacter(char c)
    {
        for (int i = 0; i < SPACE_CHARS.length; i++) {
            if (SPACE_CHARS[i] == c)
                return true;
        }

        return false;
    }

    private static final char SPACE_CHARS[] = {' ', '_'};
}