Targilim 7.1-7.5

import java.util.Scanner;
import java.util.Random;

public class testerChoice {

//Functions======================================================================================================
    //targil 7.1
    //We send links of arrays so we change them also in the main
    public static void twoToOne(String[] arg1, String[] arg2, String[] arg3, int ln){
        for(int i = 0; i<ln; i+=1){
            //if a length of both strings is good put them into third array, if not put empty string
            if(arg1[i].length()+arg2[i].length()<10) {
                arg3[i] = arg1[i] + arg2[i];
            }else{
                arg3[i]="";
            }
        }
    }

    //targil 7.2
    public static int howMuchLessWords(String[] arg1, int ln, int num, Boolean[] arg2 ){
        int temp=0;
        for(int i = 0; i<ln;i+=1){
            if(arg1[i].length()<num){
                arg2[i]=true;
                temp +=1;
            }else{
                arg2[i]=false;
            }
        }
        return temp;
    }
 //targil 7.3
    public static String getFirstLetters(String str) {
        String[] words_arr = str.split(" "); //array of words
        String temp_word; //to get only one word from array
        String temp_ot = "";//to get first letter from the word. String cause .substring returns string format
        String return_str = "";//string to return in the end
        if (words_arr.length == 0) { // if we have only one word in the basic string
            return "nos";
        }
        for (int i = 0; i < words_arr.length; i += 1) {
            temp_word = words_arr[i]; //get word from array
            temp_ot = temp_word.substring(0, 1); //get first letter with a less O(t)
            //put the first letter in case when return string is empty and if not find matches in the string
            if (return_str.length() <= 0) {
                return_str += temp_ot;
            } else {
                //check if we have a char in the our result string
                if (!return_str.contains(temp_ot.toUpperCase()) && !return_str.contains(temp_ot.toLowerCase())) {
                    return_str += temp_ot;
                }
            }
        }
        return return_str;
    }
//Targil 7.4
    public static int [] wordsAndChars(String str) {
        //separete all sentences and get their lenght
        String[] tempArr = str.split("[!.]+");
        int rightLength = tempArr.length;
        //if we DON'T! have "." or "!" in the end of the string we decrement length cause the last sentence illegal
        if (!str.substring(str.length() - 1, str.length()).contains(".") && !str.substring(str.length() - 1, str.length()).contains("!")) {
            rightLength -= 1;
        }
        //declare result array of type Integer with right length
        int[] res = new int[rightLength];
        //make loop just for legal sentences
        for (int i = 0; i < rightLength; i += 1) {
            if (tempArr[i].substring(0, 1).contains(" ")) {
                res[i] = tempArr[i].length() - 1;
            } else {
                res[i] = tempArr[i].length();
            }
        }
        return res;
    }

  //Targil 7.5
    public static boolean isKaprekarXXX(int num, int[] parts) {
        int power = num * num;
        //Sum of risha and sipa should be equal to number
        int risha = power; //risha is a first part of splited power of number.  We start risha from our number and cut it untill we have good risha and sipa or untill risha equals 0
        int sipa = 0;// sipa is the second part of splited number
        int place =1; //special increament to put our sipa in right order(from left to right)
        while ((risha + sipa != num)&&(risha!=0)) {
            sipa +=risha % 10*place;
            risha /= 10; //cut risha
            place*=10; //increament to get a right place
        }
        if (risha == 0) {
            return false;
        } else {
            parts[0] = risha;
            parts[1] = sipa;
            return true;
        }
    }

    public static boolean isStringKaprekar(String num, String[] parts){
        String power = ""+Integer.parseInt(num)*Integer.parseInt(num); //Use * for power
        String risha = power;
        String sipa = "";
        String reverse="";
        while(/*(compare risha+sipa!=num?)&&*/(risha.length()!=0)){
            reverse+=risha.substring(risha.length()-1,risha.length());
            risha=risha.substring(0, risha.length() - 1);
            sipa =new StringBuffer(reverse).reverse().toString();
        }
        return true;
    }

//main(teke of comments to work with main)================================================================================
public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        /*
        //targil 7.1
        String[] text1 = {"hi", "good", "abc"};
        String[] text2 = {"hihi", "morning", "def"};
        String[] text3 = new String[3];
        twoToOne(text1,text2, text3, text1.length());
        for(int i = 0; i<text3.length; i+=1) {
            System.out.println(text3[i]);
        }
        //targil 7.2
        String[] texter = {"hi", "good", "abjdnvndkvndkkldvc", "bubuhdfjfjf", "tudidu", "blabl", "bobr"};
        int rand_num = new Random().nextInt(15)+5;
        Boolean[] truer = new Boolean[texter.length];
        int res = howMuchLessWords(texter,texter.length, rand_num, truer);
        System.out.println("Amount of less: "+ res+" rand_num="+rand_num);
        for(int i=0; i<truer.length;i+=1) {
            if (truer[i]){
                System.out.println(i);
            }
        }

        //targil 7.3
        String work = "Mama mila Ramu vo mila Dvore";
        String res_7_3 = getFirstLetters(work);
        System.out.println("result: "+res_7_3);

         //Targil 7.4
        //for the test
        String bdika = "Hi! This is a lovely day. Please join me for breakfast.";// [2,20,28]
        String bdika2 = "Hi! This is a lovely day. Please join me for breakfast";// [2,20]
        String bdika3 = " Hi ! This is a lovely day. Please join me for breakfast.";//[3,20,28]
        int[] resArr = wordsAndChars(bdika);
        for (int i : resArr) {
            System.out.print(i + " ");
        }
        resArr = wordsAndChars(bdika2);
        System.out.println();
        for (int i : resArr) {
            System.out.print(i + " ");
        }
        System.out.println();
        resArr = wordsAndChars(bdika3);
        for (int i : resArr) {
            System.out.print(i + " ");
        }

        //Targil 7.5
        int [] res = new int [2];
        String [] res2 = new String[2];
        String st_num;
        for(int i=0; i<10000;i+=1) {
            boolean kap = isKaprekarXXX(i, res);
            if (kap) {
                System.out.println("Kaprekar: "+i + " risha: " + res[0] + " sipa: " + res[1]);
            }
        }

        boolean skap = isStringKaprekar("2728",res2);
        for(int i=0; i<10;i+=1) {
            st_num = ""+i;
            skap = isStringKaprekar(st_num,res2);
            if(skap){
                System.out.println("Kaprekar: "+i + " risha: " + res2[0] + " sipa: " + res2[1]);
            }
        }
*/