SDE - 1

This time Ninja is helping a lost passenger on a bus stop to reach his destiny with the minimum number of buses he needs to change, on the bus stop a chart is present which contains 'N' arrays. An array 'A' denotes the route that a bus will take, such that A[i] denotes the bus stop 'i'th bus will travel to.

For Example

If the bus route is [3, 6, 7], then it will travel  in sequence 
3 > 6 > 7 > 3 > 6 > 7….

You can travel between the bus stations through buses only. You are given the source bus station and destination bus station. You need to determine the minimum number of buses you need to reach the destination. If it is not possible to reach destination return -1.

Note:

Values of A[i] are distinct.

You are given an array “ARR” of positive integers. Your task is to find the number of different GCD’s in all the non-empty subsequences of the given array.

Note:

The GCD of a list of numbers is defined as the greatest number that perfectly divides all the members of the given list. For example, the GCD of 6, 8, and 10 is 2.

A subsequence of the array is a list that can be made by using some elements of the given array. All the elements can also be part of a subsequence.

For example: the array [1, 2] has subsequences: [1], [2] and [1, 2]. Similarly for the array [1, 2, 3], one of the subsequences is [1, 3].

You are given a string “S”. Your task is to rearrange the characters of a string “S”, such that it does not contain any two adjacent characters which are the same.

If it is possible to rearrange the string “S”, then print any possible arrangement. else, print “not possible” without quotes.

For Example:

For a string  “qaacde”, This string has two same adjacent characters.
So, one possible way to rearrange the string is “qacade”. Now, this string does not have two adjacent characters that are the same. 

You are given an unsorted array/list 'ARR' of 'N' integers. Your task is to return the length of the longest consecutive sequence.

The consecutive sequence is in the form ['NUM', 'NUM' + 1, 'NUM' + 2, ..., 'NUM' + L] where 'NUM' is the starting integer of the sequence and 'L' + 1 is the length of the sequence.

Note:

If there are any duplicates in the given array we will count only one of them in the consecutive sequence.

For example-

For the given 'ARR' [9,5,4,9,10,10,6].

Output = 3
The longest consecutive sequence is [4,5,6].

Follow Up:

Can you solve this in O(N) time and O(N) space complexity?

You are given a 2-dimensional array/list having N rows and M columns, which is filled with ones(1) and zeroes(0). 1 signifies land, and 0 signifies water.

A cell is said to be connected to another cell, if one cell lies immediately next to the other cell, in any of the eight directions (two vertical, two horizontal, and four diagonals).

A group of connected cells having value 1 is called an island. Your task is to find the number of such islands present in the matrix.

What is multithreading?

What is Outer left join?

Gave some sample tables and asked to perform outer left join manually as well to write a query as well.