public class NumberUtilities {
    public static String getRange(int start) {
        StringBuilder builder = new StringBuilder();

        for (int i = 0; i < start; i += 1){
            int nextNumber = i;
            builder.append(nextNumber); 
        }
        return builder.toString();

    }

    public static String getRange(int start, int stop) {
        StringBuilder builder = new StringBuilder();

        for(int i = start; i < stop; i++){
            int nextNumber = i;
            builder.append(nextNumber);
        }
        return builder.toString();
    }

    public static String getRange(int start, int stop, int step) {
        StringBuilder builder = new StringBuilder();
        for(int i = start; i < stop; i += step){
            int nextNumber = i;
            builder.append(nextNumber);
        }
        return builder.toString();
    }

    public static boolean isOdd(int input){
        if((input%2) == 1){
            return true;
        }else{
            return false;
        }
    }

    public static String getEvenNumbers(int start, int stop) {
        StringBuilder builder = new StringBuilder();
        int newStart;
        if(isOdd(start) == true){
            newStart = start + 1;
        }else{
            newStart = start;
        }
        for(int i =newStart; i < stop; i += 2){
            int nextNumber = i;
            builder.append(nextNumber);
        }

        return builder.toString();
    }

    public static String getOddNumbers(int start, int stop) {
        StringBuilder builder = new StringBuilder();
        int newStart;
        if(isOdd(start) == false){
            newStart = start + 1;
        }else{
            newStart = start;
        }
        for(int i =newStart; i < stop; i += 2){
            int nextNumber = i;
            builder.append(nextNumber);
        }
        return builder.toString();
    }

    public static String getExponentiations(int start, int stop, int exponent) {
        StringBuilder builder = new StringBuilder();
        for(int i = start; i <= stop; i += 1){
            int nextNumber = i;
            int raisedToPower = (int) Math.pow(nextNumber,exponent);
            builder.append(raisedToPower);
        }
        return builder.toString();
    }
}