Software Quality Engineer

Given a binary tree, convert this binary tree into its mirror tree.

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

Mirror of a Tree: Mirror of a Binary Tree T is another Binary Tree M(T) with left and right children of all non-leaf nodes interchanged.

Note:

1. Make in-place changes, that is, modify the nodes given a binary tree to get the required mirror tree.

You are given a string 'str' of length 'n'.

Find the minimum number of partitions in the string so that no partition is empty and every partitioned substring is a palindrome.

Example :

Input: 'str' = "aaccb"

Output: 2

Explanation: We can make a valid partition like aa | cc | b. 

Given a sequence of numbers. Find all leaders in sequence. An element is a leader if it is strictly greater than all the elements on its right side.

Note:

1. Rightmost element is always a leader.

2. The order of elements in the return sequence must be the same as the given sequence

Example:

The given sequence is 13, 14, 3, 8, 2 .

13 Not a leader because on the right side 14 is greater than 13.

14 lt is a leader because no one greater element in the right side.

3 Not a leader because on the right side 8 are greater than 3.

8 It is a leader because no one greater element on the right side.

2 It is a leader because it is the rightmost element in a sequence.

Hence there are 3 leaders in the above sequence which are 14, 8, 2.

You are given a 2-D array 'MATRIX' of dimensions N x M, of integers. You need to return the spiral path of the matrix.

Example Of Spiral Path:

You have a birthday cake and have to cut it into 8 equal pieces by making 3 cuts only. How
do you do it?

You are standing before two doors. One of the path leads to heaven and the other one leads
to hell. There are two guardians, one by each door. You know one of them always tells the truth
and the other always lies, but you don’t know who the honest one is and who the liar is.
You can only ask one question to one of them in order to find the way to heaven. What is the
question

You have been given an array/list 'ARR' of integers. Your task is to find the second largest element present in the 'ARR'.

Note:

a) Duplicate elements may be present.

b) If no such element is present return -1.

Example:

Input: Given a sequence of five numbers 2, 4, 5, 6, 8.

Output:  6

Explanation:
In the given sequence of numbers, number 8 is the largest element, followed by number 6 which is the second-largest element. Hence we return number 6 which is the second-largest element in the sequence.

You are given a Singly Linked List of integers. Return true if it has a cycle, else return false.

A cycle occurs when a node's next points back to a previous node in the list.

Example:

In the given linked list, there is a cycle, hence we return true.

i: Fragmentation- Internal and External
ii: Concepts of Kernel
iii: File Management
iv: Virtual functions and Friend Functions
v: Function Overloading And Overriding
vi: What is paging and Demand Paging?

You are given two strings 'str1' and 'str1'.

You have to tell whether these strings form an anagram pair or not.

The strings form an anagram pair if the letters of one string can be rearranged to form another string.

Pre-requisites:

Anagrams are defined as words or names that can be formed by rearranging the letters of another word. Such as "spar" can be formed by rearranging letters of "rasp". Hence, "spar" and "rasp" are anagrams. 

Other examples include:

'triangle' and 'integral'
'listen' and 'silent'

Note:

Since it is a binary problem, there is no partial marking. Marks will only be awarded if you get all the test cases correct. 

You have been given an Encrypted String where repetitions of substrings are represented as substring followed by the count of substrings.

Example: String "aabbbcdcdcd" will be encrypted as "a2b3cd3".

You need to find the 'K'th character of Decrypted String. Decrypted String would have 1-based indexing.

Note :

Input string will always be lowercase characters without any spaces.

If the count of a substring is 1 then also it will be followed by Integer '1'.
Example: "aabcdee" will be Encrypted as "a2bcd1e2"
This means it's guaranteed that each substring is followed by some Integer.

Also, the frequency of encrypted substring can be of more than one digit. For example, in "ab12c3", ab is repeated 12 times. No leading 0 is present in the frequency of substring.

The frequency of a repeated substring can also be in parts.
Example: "aaaabbbb" can also have "a2a2b3b1" as Encrypted String.

Implement a queue data structure which follows FIFO(First In First Out) property, using only the instances of the stack data structure.

Note:

1. To implement means you need to complete some predefined functions, which are supported by a normal queue such that it can efficiently handle the given input queries which are defined below.


2. The implemented queue must support the following operations of a normal queue: 

a. enQueue(data) : This function should take one argument of type integer and place the integer to the back of the queue.

b. deQueue(): This function should remove an integer from the front of the queue and also return that integer. If the queue is empty, it should return -1.

c. peek(): This function returns the element present in the front of the queue. If the queue is empty, it should return -1.

d. isEmpty(): This function should return true if the queue is empty and false otherwise.


3. You will be given q queries of 4 types:

a. 1 val - For this type of query, you need to insert the integer val to the back of the queue.

b. 2 - For this type of query, you need to remove the element from the front of the queue, and also return it.

c. 3 - For this type of query, you need to return the element present at the front of the queue(No need to remove it from the queue).

d. 4 - For this type of query, you need to return true if the queue is empty and false otherwise.


4. For every query of type:

a. 1, you do not need to return anything.

b. 2, return the integer being deQueued from the queue.

c. 3, return the integer present in the front of the queue.

d. 4, return “true” if the queue is empty, “false” otherwise.

Example

Operations: 
1 5
1 10
2
3
4

Enqueue operation 1 5: We insert 5 at the back of the queue.
Queue: [5]

Enqueue operation 1 10: We insert 10 at the back of the queue.
Queue: [5, 10]

Dequeue operation 2: We remove the element from the front of the queue, which is 5, and print it.
Output: 5
Queue: [10]

Peek operation 3: We return the element present at the front of the queue, which is 10, without removing it.
Output: 10
Queue: [10]

IsEmpty operation 4: We check if the queue is empty.
Output: False
Queue: [10]

Implement a Stack Data Structure specifically to store integer data using two Queues.

There should be two data members, both being Queues to store the data internally. You may use the inbuilt Queue.

Implement the following public functions :

1. Constructor:
It initializes the data members(queues) as required.

2. push(data) :
This function should take one argument of type integer. It pushes the element into the stack and returns nothing.

3. pop() :
It pops the element from the top of the stack and, in turn, returns the element being popped or deleted. In case the stack is empty, it returns -1.

4. top :
It returns the element being kept at the top of the stack. In case the stack is empty, it returns -1.

5. size() :
It returns the size of the stack at any given instance of time.

6. isEmpty() :
It returns a boolean value indicating whether the stack is empty or not.

Operations Performed on the Stack:

Query-1(Denoted by an integer 1): Pushes an integer data to the stack. (push function)

Query-2(Denoted by an integer 2): Pops the data kept at the top of the stack and returns it to the caller. (pop function)

Query-3(Denoted by an integer 3): Fetches and returns the data being kept at the top of the stack but doesn't remove it, unlike the pop function. (top function)

Query-4(Denoted by an integer 4): Returns the current size of the stack. (size function)

Query-5(Denoted by an integer 5): Returns a boolean value denoting whether the stack is empty or not. (isEmpty function)

Example

Operations: 
1 5
1 10
2
3
4

Enqueue operation 1 5: We insert 5 at the back of the queue.
  Queue: [5]

Enqueue operation 1 10: We insert 10 at the back of the queue.
  Queue: [5, 10]

Dequeue operation 2: We remove the element from the front of the queue, which is 5, and print it.
  Output: 5
  Queue: [10]

Peek operation 3: We return the element present at the front of the queue, which is 10, without removing it.
  Output: 10
  Queue: [10]

IsEmpty operation 4: We check if the queue is empty.
  Output: False
  Queue: [10]

There are 3 jars, namely, A, B, C. All of them are mislabeled. Following are the labels of each of the jars:

• A: Candies
• B: Sweets
• C: Candies and Sweets (mixed in a random proportion)

You can put your hand in a jar and pick only one eatable at a time. Tell the minimum number of eatable(s) that has/have to be picked in order to label the jars correctly.

There are two empty bowls in a room. You have 50 white balls and 50 black balls. After you place the balls in the bowls, a random ball will be picked from a random bowl. Distribute the balls (all of them) into the bowls to maximize the chance of picking a white ball.

100 prisoners in jail are standing in a queue facing in one direction. Each prisoner is wearing a hat of color either black or red. A prisoner can see hats of all prisoners in front of him in the queue, but cannot see his hat and hats of prisoners standing behind him.
The jailer is going to ask color of each prisoner’s hat starting from the last prisoner in queue. If a prisoner tells the correct color, then is saved, otherwise executed. How many prisoners can be saved at most if they are allowed to discuss a strategy before the jailer starts asking colors of their hats.

What is a Semaphore and operations on a semaphore?
What is context switching?

There are 4 persons (A, B, C and D) who want to cross a bridge in night.

A takes 1 minute to cross the bridge.
B takes 2 minutes to cross the bridge.
C takes 5 minutes to cross the bridge.
D takes 8 minutes to cross the bridge.
There is only one torch with them and the bridge cannot be crossed without the torch. There cannot be more than two persons on the bridge at any time, and when two people cross the bridge together, they must move at the slower person’s pace.