SDE - 1

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.

You are given a number 'N' in the form of a string 'S', your task is to find the smallest number strictly greater than the given number 'N' which is a palindrome.

Note:

1) A palindrome is a word, number, phrase, or another sequence of characters that reads the same backward as forward, such as 'naman', 'abcba', '1234321', etc
2) The numerical value of the given string 'S' will be greater than 0.
3) A single-digit number is also considered as a palindrome.
4) Note that the length of the string 'S' is nothing but the number of digits in the number 'N'.

You are given a binary tree having 'n' nodes.

The boundary nodes of a binary tree include the nodes from the left and right boundaries and the leaf nodes, each node considered once.

Figure out the boundary nodes of this binary tree in an Anti-Clockwise direction starting from the root node.

Example :

Input: Consider the binary tree A as shown in the figure:

Output: [10, 5, 3, 7, 18, 25, 20]

Explanation: As shown in the figure

The nodes on the left boundary are [10, 5, 3]

The nodes on the right boundary are [10, 20, 25]

The leaf nodes are [3, 7, 18, 25].

Please note that nodes 3 and 25 appear in two places but are considered once.