SDE - Intern

You are given an array “arr'' of integers. Your task is to find the contiguous subarray within the array which has the largest product of its elements. You have to report this maximum product.

An array c is a subarray of array d if c can be obtained from d by deletion of several elements from the beginning and several elements from the end.

For e.g.- The non-empty subarrays of an array [1,2,3] will be- [1],[2],[3],[1,2],[2,3],[1,2,3]. 

For Example:

If arr = {-3,4,5}.
All the possible non-empty contiguous subarrays of “arr” are {-3}, {4}, {5}, {-3,4}, {4,5} and {-3,4,5}.
The product of these subarrays are -3, 4, 5, -12, 20 and -60 respectively.
The maximum product is 20. Hence, the answer is 20.

Follow Up:

Can you solve this in linear time and constant space complexity?

An expression is called the postfix expression if the operator appears in the expression after the operands.

Example :

Infix expression: A + B  *  C - D 

Postfix expression:  A B + C D - *

Given a postfix expression, the task is to evaluate the expression. The answer could be very large, output your answer modulo (10^9+7). Also, use modular division when required.

Note:

1. Operators will only include the basic arithmetic operators like '*', '/', '+', and '-'.

2. The operand can contain multiple digits. 

3. The operators and operands will have space as a separator between them.

4. There won’t be any brackets in the postfix expression.

You have been given a Binary Tree of ‘N’ nodes, where the nodes have integer values. Your task is to print all nodes that don’t have a sibling node.

Note:

1. Node ‘U’ is said to be a sibling of node ‘V’ if and only if both ‘U’ and ‘V’ have the same parent.
2. Root 1 is a sibling node.

Given 'N' number of intervals, where each interval contains two integers denoting the boundaries of the interval. The task is to merge all the overlapping intervals and return the list of merged intervals sorted in ascending order.

Two intervals will be considered to be overlapping if the starting integer of one interval is less than or equal to the finishing integer of another interval, and greater than or equal to the starting integer of that interval.

Example:

for the given 5 intervals - [1,4], [3,5], [6,8], [10,12], [8,9].
Since intervals [1,4] and [3,5] overlap with each other, we will merge them into a single interval as [1,5].

Similarly [6,8] and [8,9] overlaps, we merge them into [6,9].

Interval [10,12] does not overlap with any interval.

Final List after merging overlapping intervals: [1,5], [6,9], [10,12]

Design a streaming service like Netflix and how does it onboard new content.