SDE - 1

The city of Ninjaland is analogous to the unweighted graph. The city has ‘N’ houses numbered from 1 to ‘N’ respectively and are connected by M bidirectional roads. If a road is connecting two houses ‘X’ and ‘Y’ which means you can go from ‘X’ to ‘Y’ or ‘Y’ to ‘X’. It is guaranteed that you can reach any house from any other house via some combination of roads. Two houses are directly connected by at max one road.

A path between house ‘S’ to house ‘T’ is defined as a sequence of vertices from ‘S’ to ‘T’. Where starting house is ‘S’ and the ending house is ‘T’ and there is a road connecting two consecutive houses. Basically, the path looks like this: (S , h1 , h2 , h3 , ... T). you have to find the shortest path from ‘S’ to ‘T’.

For example

In the below map of Ninjaland let say you want to go from S=1 to T=8, the shortest path is (1, 3, 8). You can also go from S=1 to T=8  via (1, 2, 5, 8)  or (1, 4, 6, 7, 8) but these paths are not shortest.

You are given an arbitrary binary tree consisting of N nodes, where each node is associated with a certain value, and two node values, a and b, you need to check if these nodes are cousins.

Two nodes are cousins of each other if they are at the same level and have different parents. Two nodes are said to be at the same level if the distance of both the nodes from the root node is the same.

A binary tree (BT) is a data structure in which each node has at most two children.

For the given binary tree:

4 and 7 are cousins of each other since they are at the same level and have different parents, 3 and 2 respectively.

You are given the root of a complete binary tree, you need to calculate the number of nodes in the given complete binary tree.

A complete binary tree is a tree in which all the levels are completely filled except the last level. Nodes in the last level are as left as possible.

For Example:

In the above complete binary tree, all the levels are filled except for the last. In the last level, all the nodes in the last level are as far left as possible.

You are given an array(ARR) of length 'N', consisting of non-negative integers. Using only these given numbers, rearrange the numbers in such a way that the resultant number thus formed is the largest possible. You cannot change the order of digits of a number.

For Example:

Given array numbers 12, 5, 34, the largest number you can form with them is 53412. There are other possible arrangements like 51234 or 34125, but they are both less than 53412.

Note:

As the final number formed after concatenation can be very large, print it as a string.

Interviewer asked me to explain the ACID properties and explain the rollback mechanism in DBMS.