Software Engineer

You are given an infinite supply of coins of each of denominations D = {D0, D1, D2, D3, ...... Dn-1}. You need to figure out the total number of ways W, in which you can make a change for value V using coins of denominations from D. Print 0, if a change isn't possible.

You are given an input string 'S'. Your task is to find and return all possible permutations of the input string.

Note:

1. The input string may contain the same characters, so there will also be the same permutations.

2. The order of permutation does not matter.

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You are given a Singly Linked List of integers. Sort the Linked List using merge sort.

Merge Sort is a Divide and Conquer algorithm. It divides the input into two halves, calls itself for the two halves, and then merges the two sorted halves. The merge() function is used for merging two halves. The merge(arr, L, M, R) is a key process that assumes that arr[L..M] and arr[M + 1...R] are sorted and merges the two sorted subarrays into one.

You are given roots of two binary trees, ‘ROOT1’ and ‘ROOT2’. You need to merge the two trees into a new binary tree. The merge rule is that if the two nodes overlap, then the sum of the two nodes values up as the new value of the merged node. Otherwise, the NOT null node will be used as the node of the new tree. Your task is to return the merged tree i.e. head of the new tree.

Note:

The merging process must start from the root nodes of both trees.

For example,

‘ROOT1’ = [1, 2, -1, -1, 3, -1, -1]  ‘ROOT2’ = [3, -1, -1].
The final tree would look like : [3, 2, -1, -1, 3, -1, -1], and the output will be printed in a pre-order way: 4 2 3.

You are given a Singly Linked List of integers. Return true if it has a cycle, else return false.

A cycle occurs when a node's next points back to a previous node in the list.

Example:

In the given linked list, there is a cycle, hence we return true.

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