Backend Developer

You're given an alphabetical string ‘S’.

Determine whether it is palindrome or not. A palindrome is a string that is equal to itself upon reversing it.

For example:

‘S’ = racecar
The reverse of ‘S’ is: racecar
Since ‘S’ is equal to its reverse. So ‘S’ is a palindrome.
Hence output will be 1.

You have been given a sorted array/list 'arr' consisting of ‘n’ elements. You are also given an integer ‘k’.

Now, your task is to find the first and last occurrence of ‘k’ in 'arr'.

Note :

1. If ‘k’ is not present in the array, then the first and the last occurrence will be -1. 
2. 'arr' may contain duplicate elements.

Example:

Input: 'arr' = [0,1,1,5] , 'k' = 1

Output: 1 2

Explanation:
If 'arr' = [0, 1, 1, 5] and 'k' = 1, then the first and last occurrence of 1 will be 1(0 - indexed) and 2.

Find the maximum salary from the given employee salary list.

Find the second maximum salary employee name from the employee table.

Aahad and Harshit always have fun by solving problems. Harshit took a sorted array consisting of distinct integers and rotated it clockwise by an unknown amount. For example, he took a sorted array = [1, 2, 3, 4, 5] and if he rotates it by 2, then the array becomes: [4, 5, 1, 2, 3].

After rotating a sorted array, Aahad needs to answer Q queries asked by Harshit, each of them is described by one integer Q[i]. which Harshit wanted him to search in the array. For each query, if he found it, he had to shout the index of the number, otherwise, he had to shout -1.

For each query, you have to complete the given method where 'key' denotes Q[i]. If the key exists in the array, return the index of the 'key', otherwise, return -1.

Note:

Can you solve each query in O(logN) ?

You are given a decimal number as input. You need to convert this number into its equivalent in the octal number system. The octal number system is the number system with a base value = 8.

A number system with base value = n means that all numbers, when written in this number system, will be represented with only digits from 0 to n-1. For example, the Binary number system has a base value = 2, so any number, when written in the binary system, will be represented using the digits 0 and 1 only.

Note:

The binary number system requires 2 digits (0-1), the Ternary number system requires 3 digits (0-2), the Octal number system requires 8 digits (0-7), and the decimal number system requires 10 digits (0-9) to represent any numeric value.

Why are Java Strings immutable in nature?

Why Java is platform-independent and JVM platform-dependent?

How would you differentiate between a String, StringBuffer, and a StringBuilder?

Design a URL Shortener

Print 1 to 100 using more than two threads(optimized approach).