DSA_Challenges_JAVA/SplitStringInPairs.java at main · Haferkorn/DSA_Challenges_JAVA · GitHub

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/*
Complete the solution so that it splits the string into pairs of two characters.
If the string contains an odd number of characters then it should replace the missing second
character of the final pair with an underscore ('_').


*/


import java.util.ArrayList;

public class SplitSting {
    public static String checkModus(String str) {
        String check;
        if (str.length() % 2 == 0) {
            check = "even";
        } else {
            check = "odd";
        }
        return check;
    }


    public static ArrayList<String> getPairs(String str) {
        String pair = "";
        ArrayList<String> arr = new ArrayList<>();
        String modus = checkModus(str);
        if (modus.equals("even")) {
            for (int i = 0; i < str.length() - 1; i += 2) {
                if (pair.length() < 2) {
                    pair += str.charAt(i);
                    pair += str.charAt(i + 1);
                    arr.add(pair);
                } else {
                    pair = "";
                    pair += str.charAt(i);
                    pair += str.charAt(i + 1);
                    arr.add(pair);
                }
            }
            return arr;
        } else if (modus.equals("odd")) {
            for (int i = 0; i < str.length() - 2; i += 2) {
                if (pair.length() < 2) {
                    pair += str.charAt(i);
                    pair += str.charAt(i + 1);
                    arr.add(pair);
                } else {
                    pair = "";
                    pair += str.charAt(i);
                    pair += str.charAt(i + 1);
                    arr.add(pair);
                }
            }
            pair="";
            pair += str.charAt(str.length()-1) + "_";
            arr.add(pair);
        }
        return arr;
    }
}