Senior Software Engineer

You are given an expression tree, your task is to evaluate the expression.

An expression tree is a binary tree where leaf nodes are integer values and internal nodes are mathematical operations.

A binary tree is a tree where every node has at most two child nodes.

Note:

There can be 4 operators: +,-,*,/. For division, you need to return the floor(a/b).

For example:

Consider the following expression tree:

While evaluating the expression tree we replace the value at a node with any operation OP by evaluating LEFTCHILD (OP) RIGHTCHILD

Here, the expression will be evaluated as 20 - 10 = 10 (FOR ‘-’), then ‘-’ will be replaced by 10 (symbolic), then we evaluate for node’+’, 10 + 10 = 20.

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?

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.

General daily life question-
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