Java Data Structures - Java List - Hackerrank Solution

 For this problem, we have  types of queries you can perform on a List:

1. Insert  at index :
   

   Insert
   x y

2. Delete the element at index :
   

   Delete
   x

Given a list, , of  integers, perform  queries on the list. Once all queries are completed, print the modified list as a single line of space-separated integers.

Input Format

The first line contains an integer,  (the initial number of elements in ).
The second line contains  space-separated integers describing .
The third line contains an integer,  (the number of queries).
The  subsequent lines describe the queries, and each query is described over two lines:

• If the first line of a query contains the String Insert, then the second line contains two space separated integers , and the value  must be inserted into  at index .
• If the first line of a query contains the String Delete, then the second line contains index , whose element must be deleted from .

Constraints

• 
  
• 
  
• Each element in is a 32-bit integer.

Output Format

Print the updated list  as a single line of space-separated integers.

Sample Input

5
12 0 1 78 12
2
Insert
5 23
Delete
0

Sample Output

0 1 78 12 23

Explanation

 Insert 23 at index .

 Delete the element at index .

Having performed all  queries, we print  as a single line of space-separated integers.

Solution

import java.io.*;

import java.util.*;

class Solution {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        // Enter number of elements for List

        int n = sc.nextInt();

        ArrayList<Integer> list = new ArrayList<Integer>();

        // Adding elements to the list

        for (int i = 0; i < n; i++) {

            list.add(sc.nextInt());

        }

        // Getting no of queries

        int q = sc.nextInt();

        // Performing all the queries

        for (int i = 0; i < q; i++) {

            String queryType = sc.next();

            if(queryType.equals("Insert")){

                int index = sc.nextInt();

                int value = sc.nextInt();

                list.add(index, value);

            }else if(queryType.equals("Delete")){

                int index = sc.nextInt();

                list.remove(index);

            }

        }

        String resString = Arrays.toString(list.toArray());

        resString = resString.replaceAll(",","");

        resString = resString.substring(1,resString.length()-1);

        System.out.println(resString);

    }

}