SDE - Intern

Make an Entry Management web app.
Check-In: The Visitor is asked to enter his/her and Host’s details. Thereafter, an SMS and E-mail is sent to the Host giving the details of the Visitor.
Check Out: The Visitor is asked to enter his/her E-mail Id for verification and after it, the visitor is checked out. Thereafter, an email is sent to the visitor containing his/her visit details.

Design a data structure that stores a mapping of a key to a given value and supports the following operations in constant time.

1. INSERT(key, value): Inserts an integer value to the data structure against a string type key if not already present. If already present, it updates the value of the key with the new one. This function will not return anything.

2. DELETE(key): Removes the key from the data structure if present. It doesn't return anything.

3. SEARCH(key): It searches for the key in the data structure. In case it is present, return true. Otherwise, return false.

4. GET(key): It returns the integer value stored against the given key. If the key is not present, return -1. 

5. GET_SIZE(): It returns an integer value denoting the size of the data structure. 

6. IS_EMPTY(): It returns a boolean value, denoting whether the data structure is empty or not. 

Note :

1. Key is always a string value.
2. Value can never be -1.

Operations Performed :

First(Denoted by integer value 1):  Insertion to the Data Structure. It is done in a pair of (key, value).

Second(Denoted by integer value 2):  Deletion of a key from the Data Structure.

Third(Denoted by integer value 3): Search a given key in the Data Structure.

Fourth(Denoted by integer value 4): Retrieve the value for a given key from the Data Structure.

Fifth(Denoted by integer value 5): Retrieve the size of the Data Structure.

Sixth(Denoted by integer value 6): Retrieve whether the Data Structure is empty or not.

You are given two arbitrary binary trees. You need to find if both trees are isomorphic or not.

Two binary trees are said to be isomorphic with each other, if one of the trees can be obtained from the other, by performing the following operation any number of times:

Choose a node of the tree, swap its left and right subtree i.e the left subtree will become the right one, and vice versa.

Note:

1. A binary tree is a tree in which each node has at most two children.   

2. The left subtree of a node, is the tree in which the left child of the node is the root of that tree, and the same holds for the right subtree.

3. The given operation can be performed on any node at any level of the given trees.  

4. Two empty trees are also said to be isomorphic.

Mainly 3 subjects: Database Management System, Object-Oriented Programming and Operating Systems. A few questions were asked from these.