SDE - 1

You have been given an array 'PRICES' consisting of 'N' integers where PRICES[i] denotes the price of a given stock on the i-th day. You are also given an integer 'K' denoting the number of possible transactions you can make.

Your task is to find the maximum profit in at most K transactions. A valid transaction involves buying a stock and then selling it.

Note

You can’t engage in multiple transactions simultaneously, i.e. you must sell the stock before rebuying it.

For Example

Input: N = 6 , PRICES = [3, 2, 6, 5, 0, 3] and K = 2.
Output: 7

Explanation : The optimal way to get maximum profit is to buy the stock on day 2(price = 2) and sell it on day 3(price = 6) and rebuy it on day 5(price = 0) and sell it on day 6(price = 3). The maximum profit will be (6 - 2) + (3 - 0) = 7.

You are given ‘n’ cities, some of which are connected by bidirectional roads. You are also given an ‘n x n’ matrix i.e. ‘roads’, where if city ‘i’ and ‘j’ are connected by a road then ‘roads[i][j]'= 1, otherwise ‘roads[i][j]' = 0.

A province is a group of cities that are either directly or indirectly connected to each other through roads.

The goal is to count and return the total number of such provinces in the given matrix.

Example:

n = 4, roads = [ [1, 1, 1, 0],
                 [1, 1, 1, 0],
                 [1, 1, 1, 0],
                 [0, 0, 0, 1] ]

So, there are ‘2’ provinces.

Note:

1. A city is connected to itself. So, for every city ‘i’, ‘roads[i][i] = 1’.

You are given an array/list ARR consisting of N integers. Your task is to find all the distinct triplets present in the array which adds up to a given number K.

An array is said to have a triplet {ARR[i], ARR[j], ARR[k]} with sum = 'K' if there exists three indices i, j and k such that i!=j, j!=k and i!=j and ARR[i] + ARR[j] + ARR[k] = 'K'.

Note:

1. You can return the list of values in any order. For example, if a valid triplet is {1, 2, -3}, then {2, -3, 1}, {-3, 2, 1} etc is also valid triplet. Also, the ordering of different triplets can be random i.e if there are more than one valid triplets, you can return them in any order.
2. The elements in the array need not be distinct.
3. If no such triplet is present in the array, then return an empty list, and the output printed for such a test case will be "-1".

Given that integers are read from a data stream. Your task is to find the median of the elements read so far.

Median is the middle value in an ordered integer list. If the size of the list is even there is no middle value. So the median is the floor of the average of the two middle values.

For example :

[2,3,4] - median is 3.
[2,3] - median is floor((2+3)/2) = 2.

There is a Binary Search Tree (BST) consisting of ‘N’ nodes. Each node of this BST has some integer data.

You are given the root node of this BST, and an integer ‘X’. Return true if there is a node in BST having data equal to ‘X’, otherwise return false.

A binary search tree (BST) is a binary tree data structure that has the following properties:

1. The left subtree of a node contains only nodes with data less than the node’s data.

2. The right subtree of a node contains only nodes with data greater than the node’s data.

3. The left and right subtrees must also be binary search trees.

Note:

It is guaranteed that all nodes have distinct data.