SDE - 1

You are given an array Arr consisting of n integers, you need to find all the distinct triplets present in the array which adds up to zero.

An array is said to have a triplet {arr[i], arr[j], arr[k]} with 0 sum if there exists three indices i, j and k such that i!=j, j!=k and i!=k and arr[i] + arr[j] + arr[k] = 0.

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".

You are given two sorted linked lists. You have to merge them to produce a combined sorted linked list. You need to return the head of the final linked list.

Note:

The given linked lists may or may not be null.

For example:

If the first list is: 1 -> 4 -> 5 -> NULL and the second list is: 2 -> 3 -> 5 -> NULL

The final list would be: 1 -> 2 -> 3 -> 4 -> 5 -> 5 -> NULL

You are given a binary tree having 'n' nodes. Each node of the tree has an integer value.

Your task is to find the maximum possible sum of a simple path between any two nodes (possibly the same) of the given tree.

A simple path is a path between any two nodes of a tree, such that no edge in the path is repeated twice. The sum of a simple path is defined as the summation of all node values in a path.

You are given a directed graph having ‘N’ nodes. A matrix ‘EDGES’ of size M x 2 is given which represents the ‘M’ edges such that there is an edge directed from node EDGES[i][0] to node EDGES[i][1].

Find whether the graph contains a cycle or not, return true if a cycle is present in the given directed graph else return false.

For Example :

In the following directed graph has a cycle i.e. B->C->E->D->B.

Note :

1. The cycle must contain at least two nodes.
2. It is guaranteed that the given graph has no self-loops in the graph.
3. The graph may or may not be connected.
4. Nodes are numbered from 1 to N.
5. Your solution will run on multiple test cases. If you are using global variables make sure to clear them.