## Java Arraylist HackerRank Solution

Sometimes it’s better to use dynamic size arrays. Java’s Arraylist can provide you this feature. Try to solve this problem using Arraylist.

You are given n lines. In each line there are zero or more integers. You need to answer a few queries where you need to tell the number located in yth position of xth line.

Take your input from System.in.

**Input Format**

The first line has an integer n. In each of the next n lines there will be an integer d denoting number of integers on that line and then there will be d space-separated integers. In the next line there will be an integer q denoting number of queries. Each query will consist of two integers x and y.

**Constraints**

- 1<=n<=20000
- 0<=d<=50000
- 1<=q<=1000
- 1<=x<=n

Each number will fit in signed integer.

Total number of integers in n lines will not cross 10^5.

**Output Format**

In each line, output the number located in yth position of xth line. If there is no such position, just print “ERROR!”

**Sample Input**

5 5 41 77 74 22 44 1 12 4 37 34 36 52 0 3 20 22 33 5 1 3 3 4 3 1 4 3 5 5

**Sample Output**

74 52 37 ERROR! ERROR!

**Explanation**

The diagram below explains the queries:

Code Solution:

#Java Arraylist HackerRank Solution import java.io.*; import java.util.*; 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 in = new Scanner(System.in); int n = in.nextInt(); int d,q,x,y; ArrayList[] set = new ArrayList[n]; for(int i=0;i<n;i++){ d = in.nextInt(); set[i] = new ArrayList(); for(int j=0;j<d;j++){ set[i].add(in.nextInt()); } } q=in.nextInt(); for(int i=0;i<q;i++){ x=in.nextInt(); y=in.nextInt(); try{ System.out.println(set[x-1].get(y-1)); } catch(Exception e){ System.out.println("ERROR!"); } } } } #Java Arraylist HackerRank Solution

Disclaimer: This problem is originally created and published by HackerRank, we only provide solutions to this problem. Hence, doesn’t guarantee the truthfulness of the problem. This is only for information purposes.