SDE - 1

You are given a string, ‘S’. You need to reverse the string where characters that are not an alphabet stay in the same place, and the rest reverse their positions.

Eg: “a-bcd” becomes “d-cba”

You are given an array/list 'ARR' consisting of N integers, which contains elements only in the range 0 to N - 1. Some of the elements may be repeated in 'ARR'. Your task is to find all such duplicate elements.

Note:

1. All the elements are in the range 0 to N - 1.
2. The elements may not be in sorted order.
3. You can return the duplicate elements in any order.
4. If there are no duplicates present then return an empty array.

You are given an array of integers ‘ARR’. Sort the array by performing a series of pancake flips. In one pancake flip, we do the following steps:

Choose an integer ‘K’ where 1 <= ‘K’ <= ARR.LENGTH.
Reverse the sub-array ARR[0, , ,K-1] (0-indexed).

Your task is to sort the array and return all the series of positions from where you flipped the array.

Note:

1. The array given will have elements between 1 to ‘N’, where N is the size of the array, and all elements of the array will be unique.
2. Any valid answer that sorts the array within 10 * array’s length flips will be judged as correct.
3. If the array is already sorted return an empty list. 

For example:

If ARR = [3,2,1] and we performed a pancake flip choosing K = 3, we reverse the sub-array [3,2,1], so ARR = [1,2,3] .  Hence the array becomes sorted therefore return {3}.

Ninja is given an integer ‘N’. One day Ninja decides to do the sum of all digits and replace the ‘N’ with the sum of digits until it becomes less than 10. Ninja wants to find what will be the value of ‘N’ after applying this operation.

Help Ninja in finding out this value.

You are given an integer, all you have to do is to find whether this number is a Fibonacci number or not.

Fn is said to be a Fibonacci sequence such that each number in Fn is the sum of its two preceding numbers, starting with 0 and 1.

Fn = F(n-1) + F(n-2)

fn is said to be a Fibonacci number if it is a part of the Fn/Fibonacci sequence.

Write SQL query to find second highest salary from a Table.

You are given a string 'S' of length 'N', you need to find the frequency of each of the characters from ‘a’ to ‘z’ in the given string.

Example :

Given 'S' : abcdg
Then output will be : 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

What is Normalization and 3NF?