Question

Write a queue client, "LineNum," that takes an integer command line argument “n” and prints the nth string from the first string found on standard input. [MO6.2]

Please note that you would need to use a queue to implement it for full credit. You should add the strings inputted by the user to a queue using the enqueue method. Then you should remove and return "n" strings from the queue using the dequeue method. The nth string that is returned by the dequeue method should then be printed out.

• Sample runs would be as follows.
  
  >java LineNum 2
  apple
  save
  that
  is
  too
  me
  <CTRL-D>
  2 from the first is save
  
  >java LineNum 3
  this
  is
  not
  a
  shorter
  version
  <CTRL-D>
  3 from the first is not

Answer 1

Code -

import java.util.*;

public class LineNum {
public static void main(String[] args) {
   //read command line arguement from user
   int n = Integer.parseInt(args[0]);
//initialize a queue
   Queue<String> elements = new LinkedList<>();
   //using try catch to read user input and when user press CTRL+D it will exit
   try {
   //byter array to store user enter data
byte[] byteArray = new byte[1024];
//continue for loop till user enter CTRL + D
for (int i; (i = System.in.read(byteArray)) != -1;) {
//convert the byteArray to string
String userInput = new String(byteArray, 0, i);
//add the element to the queue
elements.add(userInput);
}
} catch (Exception e) {
e.printStackTrace();
}
   //dequque element till the n - 1
   for(int i = 0 ;i < n-1; i++){
elements.remove();
   }
   //print the peek element
   System.out.println(n+" from the first is "+elements.peek());

}
}

Input ->

java LineNum 3

this                                                                                                                            

is                                                                                                                              

not                                                                                                                             

a                                                                                                                               

shorter                                                                                                                         

version       

CTRL + D   

3 from the first is not

Output -