2D arraylist NoSuchElementException

Question

I am trying to create a 2D ArrayList and add values to it. For some reason I keep getting a NoSuchElementException .

Here is the problem I am trying to solve: https://www.hackerrank.com/challenges/java-arraylist

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
               Scanner input = new Scanner(System.in);
               int TestCases = input.nextInt();
               ArrayList<ArrayList<Integer>> listOfLists = new ArrayList<ArrayList<Integer>>();

               List<ArrayList<Integer>> Sdarraylist = new ArrayList<ArrayList<Integer>>();

                //ArrayList<ArrayList<String>> 2darraylist = new ArrayList<>();
                //ArrayList<String> 1darraylist=new ArrayList<>();

               for(int i=0;i<TestCases;i++){

                   ArrayList<Integer> Fdarraylist=new ArrayList<Integer>();
                   //size of Arraylist
                   int NumbersOnCurrentLine = input.nextInt();
                   for(int j=0;i<NumbersOnCurrentLine;j++){
                     //add numbers on the current line to the list
                     Fdarraylist.add(input.nextInt());
                   }
                 Sdarraylist.add(Fdarraylist);
               }                
// data.add(new ArrayList<String>());
 //data.get(0).add("String");

    }
}

Answer 1

That exception occurs when you try to read from an input, but no input is available. One workaround would be to use use the hasNextInt() method to make sure there is readable input available. ex)

if (input.hasNextInt()) {
    Fdarraylist.add(input.nextInt());
}

---

This could be the result of the input saying there are three numbers on the current line, when in reality there are only two.

1
3 1 4 <= would cause exception.