SDE - 1

You have been given a Binary Tree of integers. You are supposed to return the level order traversal of the given tree.

For example:

For the given binary tree

The level order traversal will be {1,2,3,4,5,6,7}.

You are given the schedule of 'N' meetings with their start time 'Start[i]' and end time 'End[i]'.

You have only 1 meeting room. So, you need to return the maximum number of meetings you can organize.

Note:

The start time of one chosen meeting can’t be equal to the end time of the other chosen meeting.

For example:

'N' = 3, Start = [1, 3, 6], End = [4, 8, 7].

You can organize a maximum of 2 meetings. Meeting number 1 from 1 to 4, Meeting number 3 from 6 to 7.

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 an integer ‘N’, your task is to find and return the N’th Fibonacci number using matrix exponentiation.

Since the answer can be very large, return the answer modulo 10^9 +7.

Fibonacci number is calculated using the following formula:

F(n) = F(n-1) + F(n-2), 
Where, F(1) = F(2) = 1.

For Example:

For ‘N’ = 5, the output will be 5.

A permutation is a mathematical technique that determines the number of possible arrangements in a set when the order of the arrangements matters. A string of length 'N' has 'N'! permutations.

Given an array of distinct integers, return all the possible permutations of the array.

Example:

'ARR[]' = [1, 2]

The size of the array is 2. So, the total number of permutations is 2! = 2. The possible permutations are [1, 2] (the array itself) and [2,1] where the position of element 1 in the original array is swapped with element 2 and vice-versa.   

Note:

1. All the numbers in the array are unique.

2. You can return the answer in any order.

3. The original array is also a permutation of the given array.

You are given an array of size ‘n’ to find the minimum number of steps to either convert it into either non-decreasing or non-increasing array. In one step you can either increment or decrement the element of the array.