# Java Arraylist HackerRank Solution

## 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.

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++){
}
}
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.