You are given the root node of a binary tree with N nodes, whose nodes have integer values. Your task is to find the maximum depth of the given Binary tree.
Depth of a binary tree is the same as its height. In simpler terms, you have to find the total number of nodes encountered while moving from the root node to the farthest leaf node, along the longest path of the binary tree.

Given an array/list of integers of length ‘N’, there is a sliding window of size ‘K’ which moves from the beginning of the array, to the very end. You can only see the ‘K’ numbers in a particular window at a time. For each of the 'N'-'K'+1 different windows thus formed, you are supposed to return the maximum element in each of them, from the given array/list.

Given a string (STR) of length N, you have to create a new string by performing the following operation:
Take the smallest character from the first 'K' characters of STR, remove it from STR and append it to the new string.

You are given an array of N elements. This array represents the digits of a number. In an operation, you can swap the value at any two indices. Your task is to find the maximum number by using operation at most once.

You are given an array Arr consisting of N integers. You need to find the equilibrium index of the array.
An index is considered as an equilibrium index if the sum of elements of the array to the left of that index is equal to the sum of elements to the right of it.