SDE - 1

You are given two binary trees with 'n' and 'm' nodes respectively.

You need to return true if the two trees are identical. Otherwise, return false.

Example:

For the trees given below:- 

The given trees are identical as:-
1. The number of nodes in both trees is the same. 
2. The number of edges in both trees is the same. 
3. The data for root for both the trees is the same i.e 5. 
4. The data of root -> left (root’s left child) for both the trees is the same i.e 2.
5. The data of root -> right (root’s right child) for both the trees is the same i.e 3.
6. The data of root -> right -> left ( left child of root’s right child) for both the trees is the same i.e 6.
7. Nodes with data 2 and 6 are the leaf nodes for both the binary trees. 

Given two strings S and T consisting of lower case English letters. The task is to count the distinct occurrences of T in S as a subsequence.

A subsequence is a sequence generated from a string after deleting some or no characters of the string without changing the order of the remaining string characters. (i.e. “ace” is a subsequence of “abcde” while “aec” is not).

For example, for the strings S = “banana” and T=”ban”, output is 3 as T appears in S as below three subsequences.

[ban], [ba n], [b an ]

You have been given a singly Linked List of 'N' nodes with integer data and an integer 'K'.

Your task is to remove the 'K'th node from the end of the given Linked List and return the head of the modified linked list.

Example:

Input : 1 -> 2 -> 3 -> 4 -> 'NULL'  and  'K' = 2
Output: 1 -> 2 -> 4 -> 'NULL'
Explanation:
After removing the second node from the end, the linked list become 1 -> 2 -> 4 -> 'NULL'.

What are semaphores? 
Follow up questions - 
What is critical section problem?
Code it with multithreading program. (i used java)
What is thread? What is process? Differences between them.
Execution flow in multithreaded program, with preemption and critical section problem happening. And how semaphores are actually helping to overcome this problem.

He asked me some system calls like fork. 
And some basic linux commands.

What is Dynamic Programming?Explain with example.

You are given a binary tree consisting of 'n' nodes.

Convert the given binary tree into a linked list where the linked list nodes follow the same order as the pre-order traversal of the given binary tree.

Use the right pointer of the binary tree as the “next” pointer for the linked list and set the left pointer to NULL.

Use these nodes only. Do not create extra nodes.

Example :

Input: Let the binary be as shown in the figure:

Output: Linked List: 15 -> 40 -> 62 -> 10 -> 20 -> NULL

Explanation: As shown in the figure, the right child of every node points to the next node, while the left node points to null.

Also, the nodes are in the same order as the pre-order traversal of the binary tree.