SDE - 2

You are given a straight line starting at 0 to 10^9. You start at zero, and there are ‘N’ tasks you can perform. ‘ith’ task is located at point 'Task[i][0]' in the line and requires 'Task[i][1]' time to be performed.

To perform the task, you need to reach the point 'Task[i][0]' and spend 'Task[i][1]' time at that location. e.g. (5,8) lies at five, so travel distance is five, and work effort is 8.

It takes one second to travel one unit of the path.

Now, we are given a total of ‘totalTime’ seconds, and we need to complete as many tasks as possible and reach back to starting position.

Find the max number of tasks that you can finish in ‘totalTime’.

For example:

3 tasks and 16 units of total time.
Task = [( 2, 8 ) , ( 4, 5) , ( 5, 1)]
( 2, 8 ) -> task 1 at position 2 in line and takes 8 sec to complete.
( 4, 5)  -> task 2 at position 4 in line and takes 5 sec to complete.
( 5, 1) -> task 3 at position 5 in line and takes 1 sec to complete.
Skipping the first task leaves us enough time to complete the other two tasks. Going to the location of the third task and coming back costs 2x5 =10 sec, and performing tasks at locations 4 and 5 cost us 5+1 = 6 sec. 
Total time spent will be 10+6=16 sec.

Ninja loves beautiful numbers and also has two integers, ‘L’ and ‘R’, denoting an interval [L, R].

Given the interval [L, R], Ninja wants you to find the number of Beautiful numbers in the interval.

A Beautiful Number is a number that:

Becomes 1 by repeatedly replacing the number with the sum of squares of its digits.

If the number does not become 1, then it’s not a Beautiful Number.

For example, given interval = [1, 3]

We see that 1 is a Beautiful Number but 2,3 are not. Hence the answer is 1.

Output the single integer, the sum of all Beautiful Numbers in the given range.

Example:

Input: ‘L’ = ‘1’ ,  'R' = ‘3’

Output: 1

As ‘1’ is the only Beautiful Number.

3 is not Beautiful as, 
3 -> 9
9 -> 81
81 -> 65
65 -> 61 … and so on
It can be shown that we cannot get 1. 

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) ?

How can we ensure backward compatibility while doing any changes in any API.

You have been given a linked list of integers. Your task is to write a function that deletes a node from a given position, 'POS'.

Note :

Assume that the Indexing for the linked list always starts from 0.

If the position is greater than or equal to the length of the linked list, you should return the same linked list without any change.

Illustration :

The following images depict how the deletion has been performed.

Image-I :

Image-II :

You are given an array consisting of 0s and 1s. You need to find the length of the largest subarray with an equal number of 0s and 1s.

For example:

If the given array is: [0, 0, 1, 0, 1] The largest subarray would be: [0, 1, 0, 1] (last 4 elements) having length 4.

Given an integer ‘N’ representing the number of pairs of parentheses, Find all the possible combinations of balanced parentheses with the given number of pairs of parentheses.

Note :

Conditions for valid parentheses:
1. All open brackets must be closed by the closing brackets.

2. Open brackets must be closed in the correct order.

For Example :

()()()() is a valid parentheses.
)()()( is not a valid parentheses.

Given an array/list 'ARR' of integers and an integer ‘K’. You are supposed to return the length of the shortest subarray that has a sum greater than or equal to ‘K’. If there is no subarray with a sum greater than or equal to K, then return -1.

Note :

An array ‘B’ is a subarray of an array ‘A’ if ‘B’ that can be obtained by deletion of, several elements(possibly none) from the start of ‘A’ and several elements(possibly none) from the end of ‘A’. 

You have been given a binary tree of integers with N number of nodes. Your task is to check if that input tree is a BST (Binary Search Tree) or not.

A binary search tree (BST) is a binary tree data structure which has the following properties.

• The left subtree of a node contains only nodes with data less than the node’s data.
• The right subtree of a node contains only nodes with data greater than the node’s data.
• Both the left and right subtrees must also be binary search trees.

Example :

Answer :

Level 1: 

All the nodes in the left subtree of 4 (2, 1, 3) are smaller 
than 4, all the nodes in the right subtree of the 4 (5) are 
larger than 4.

Level 2 :

For node 2:
All the nodes in the left subtree of 2 (1) are smaller than 
2, all the nodes in the right subtree of the 2 (3) are larger than 2.
For node 5:
The left and right subtrees for node 5 are empty.

Level 3:

For node 1:
The left and right subtrees for node 1 are empty.
For node 3:
The left and right subtrees for node 3 are empty.

Because all the nodes follow the property of a binary search tree, the above tree is a binary search tree.

System design for movie reservation system (LLD) ,requirement gathering ,DB schema design, APIs that need to be used.

Optimising given SQL queries and DB locks like select on update etc

• Spring boot questions on synchronized , java locks, etc
• Streams in java and multithreading.

Current company and CTC.
Reason for job change.
Questions on projects in resume.
Questions on cloud providers like AWS, GCP etc…
And other questions like process followed while given a task.
Questions on open with full stack areas and discussion of FE work which was done.