You are given the head of a linked list, and an integer k.

Given an array of unique integers, arr, where each integer arr[i] is strictly greater than 1.

Given a binary string s and an integer k.

You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.

Given the root of a binary tree, then value v and depth d, you need to add a row of nodes with value v at the given depth d. The root node is at depth 1.

A valid encoding of an array of words is any reference string s and array of indices indices such that:

Given the head of a linked list, remove the nth node from the end of the list and return its head.