Question

In Java

1. IntegerStream: An integer stream produces a continuous sequence of integers, starting at some initial integer. Each subsequence integer produced should be one more than the previous integer. The class will need the following methods and constructors:

   1. The constructor takes an integer that represents the first value returned by the stream.

   2. next(): Takes no input and returns the next value of the stream starting at the initial value. Each time next is called, the number returned should be one more than what was returned the previous time next was called,

   For example, if you create stream = new IntegerStream(10); then calling stream.next() should produce the following:

   > stream.next()
   10
   > stream.next()
   11
   > stream.next()
   12
   

2. StringStream: A string stream produces a continuous sequence of strings that consist of lower case letters, in lexicographical order. (The strings in lexicographical order are: { "", "a", "b", ..., "z", "aa", "ab", ..., "az", "ba", "bb", ..., "bz", ..., "zz", "aaa", "aab", ...}.) The class will need the following methods and constructors:

   1. The constructor takes a String that represents the first value returned by the stream. (The behavior if the input is not all lowercase letters is up to you.)

   2. next: Takes no input and returns the next value of the stream, i.e. it returns the string that is next in the lexicographical ordering from the previous value returned by next.

   For example, if you create stream = new StringStream("pez"); then calling stream.next() should produce the following:

   > stream.next()
   "pez"
   > stream.next()
   "pfa"
   > stream.next()
   "pfb"

Answer 1

The java code is as follows:

public class IntegerStream {
    private int number;
    // defining IntegerStram constructor which take one value
    IntegerStream(int value){
        number=value;
    }
    // Defining next method which returns an integer
    int next(){
        return  number++;
    }
    public  static  void main(String args[]){
        // creating the object for IntegerStream class
        IntegerStream stream = new IntegerStream(10);
        System.out.println(stream.next());
        System.out.println(stream.next());
        System.out.println(stream.next());

    }
}

output:

The output is at the bottom of the page

The java code for StringStramer is:

public class StringStream {
    String str;
    static  int count =0;
    StringStream(String value){
        str=value;
    }
    String next()
    {
        if (count==0){
            count++;
            return str;

        }else{
            // if string is empty
            if (str == "")
                return "a";

            // Find first character from
            // right which is not z.
            int i = str.length() - 1;
            while (str.charAt(i) == 'z' && i >= 0)

                i--;


            // If all characters are 'z',
            // append an 'a' at the end.
            if (i == -1)
                str = str + 'a';

                // If there are some
                // non-z characters
            else

                str = str.substring(0, i) +
                        (char)((int)(str.charAt(i)) + 1) +
                        str.substring(i + 1);
            if (i==str.length() - 2){
                str =changeCharInPosition(str.length()-1, 'a', str);
            }
            return str;
        }

    }
    public String changeCharInPosition(int position, char ch, String str){
        char[] charArray = str.toCharArray();
        charArray[position] = ch;
        return new String(charArray);
    }

    public  static  void main(String args[]){
        // creating the object for StringStream class
        StringStream stream = new StringStream("pez");
        System.out.println(stream.next());
        System.out.println(stream.next());
        System.out.println(stream.next());

    }
}

I hope you got the answer and understand it.

Thank you:):)