StringsAndThings.java

package io.zipcoder;


/**
 * @author tariq
 */
public class StringsAndThings {

    /**
     * Given a string, count the number of words ending in 'y' or 'z' -- so the 'y' in "heavy" and the 'z' in "fez" count,
     * but not the 'y' in "yellow" (not case sensitive). We'll say that a y or z is at the end of a word if there is not an alphabetic
     * letter immediately following it. (Note: Character.isLetter(char) tests if a char is an alphabetic letter.)
     * example : countYZ("fez day"); // Should return 2
     *           countYZ("day fez"); // Should return 2
     *           countYZ("day fyyyz"); // Should return 2
     */
    public Integer countYZ(String input){
        int count = 0;
       String[] arrayOfWords = input.split(" ");
        for (int i = 0; i < arrayOfWords.length; i++) {
            String word = arrayOfWords[i];
            int numberOfCharactersInWord = word.length();
            int lastIndex = numberOfCharactersInWord -1;
            char lastCharacter = word.charAt(lastIndex);
            if(lastCharacter == 'y' || lastCharacter == 'z'){

                count++;

            }
            //if the last character of word is equals to y or z

        }
        return count;
    }

    /**
     * Given two strings, base and remove, return a version of the base string where all instances of the remove string have
     * been removed (not case sensitive). You may assume that the remove string is length 1 or more.
     * Remove only non-overlapping instances, so with "xxx" removing "xx" leaves "x".
     *
     * example : removeString("Hello there", "llo") // Should return "He there"
     *           removeString("Hello there", "e") //  Should return "Hllo thr"
     *           removeString("Hello there", "x") // Should return "Hello there"
     */
    //
    //nested loop

    public String removeString(String base, String remove){
       String answer = base.replaceAll(remove, "");

        return answer;
    }
//
    /**
     * Given a string, return true if the number of appearances of "is" anywhere in
     * the string is equal to the number of appearances of "not" anywhere in the string
     * (case sensitive)
     *
     * example : containsEqualNumberOfIsAndNot("This is not")  // Should return false
     *           containsEqualNumberOfIsAndNot("This is notnot") // Should return true
     *           containsEqualNumberOfIsAndNot("noisxxnotyynotxisi") // Should return true
     */
    public Boolean containsEqualNumberOfIsAndNot(String input){
        //find the number of "is" appearances
        //find the number of "not appearances
        //compare number of appearances

        int countIs = 0;
        int countNot = 0;
        int indexOf = input.indexOf("not");
        while (indexOf >= 0){
            input = input.replaceFirst("not", " ");
            indexOf = input.indexOf("not");
            countNot++;
        }
        indexOf = input.indexOf("is");

        while (indexOf >= 0){
            input = input.replaceFirst("is" , " ");
            indexOf = input.indexOf("is");
            countIs++;
        }


        return countIs == countNot;
    }

    /**
     * We'll say that a lowercase 'g' in a string is "happy" if there is another
     * 'g' immediately to its left or right.
     * Return true if all the g's in the given string are happy.
     * example : gHappy("xxggxx") // Should return  true
     *           gHappy("xxgxx") // Should return  false
     *           gHappy("xxggyygxx") // Should return  false
     */

    public Boolean gIsHappy(String input) {
       boolean returnMe = true;
        for (int i = 0; i < input.length(); i++) {
            if (input.charAt(i) == 'g') {
                if (input.charAt(i + 1) != 'g' && input.charAt(i - 1) != 'g') {
                    returnMe = false;
                }
            }
        }
        return returnMe;
    }


    /**
     * We'll say that a "triple" in a string is a char appearing three times in a row.
     * Return the number of triples in the given string. The triples may overlap.
     * example :  countTriple("abcXXXabc") // Should return 1
     *            countTriple("xxxabyyyycd") // Should return 3
     *            countTriple("a") // Should return 0
     */
    /*
    * identify the number of 3x repeating characters
    * have that number of 3x repeating characters add to a counter
    * */
    public Integer countTriple(String input){
        int counter = 0;
        for (int i = 1; i < input.length() - 1; i++){
            if(input.charAt(i) == input.charAt(i - 1) && input.charAt(i) == input.charAt(i + 1)){

               counter++;
            }
        }
        return counter;
    }
}