SDE - 1

You are given the head node of a singly linked list 'head'. Your task is to modify the linked list in such a way that all the even valued nodes appear before the all odd valued node and order of nodes remain the same.

Example :-

The given singly linked list is  6 -> 5 -> 3 -> 4 -> 7 -> 1 -> 2 

The modified linked list should have all even values in starting and odd values in the end.

You have been given a Binary Tree of distinct integers and two nodes ‘X’ and ‘Y’. You are supposed to return the LCA (Lowest Common Ancestor) of ‘X’ and ‘Y’.

The LCA of ‘X’ and ‘Y’ in the binary tree is the shared ancestor of ‘X’ and ‘Y’ that is located farthest from the root.

Note :

You may assume that given ‘X’ and ‘Y’ definitely exist in the given binary tree.

For example :

For the given binary tree

LCA of ‘X’ and ‘Y’ is highlighted in yellow colour.

Given an array/list of integers of length ‘N’, there is a sliding window of size ‘K’ which moves from the beginning of the array, to the very end. You can only see the ‘K’ numbers in a particular window at a time. For each of the 'N'-'K'+1 different windows thus formed, you are supposed to return the maximum element in each of them, from the given array/list.

You have been given an array 'ARR' of 'N' distinct elements.

Your task is to find the minimum no. of swaps required to sort the array.

For example:

For the given input array [4, 3, 2, 1], the minimum no. of swaps required to sort the array is 2, i.e. swap index 0 with 3 and 1 with 2 to form the sorted array [1, 2, 3, 4].

You have been given a Binary Tree of 'n' nodes, where the nodes have integer values

Print the left view of the binary tree.

Example :

If the input tree is as depicted in the picture: 

The Left View of the tree will be:  2 35 2 

'N' students are standing in a row. You are given the height of every student standing in the row. Your task is to find the longest strictly increasing subsequence of heights from the row such that the relative order of the students does not change.

A subsequence is a sequence that can be derived from another sequence by deleting zero or more elements without changing the order of the remaining elements.