SDE - 1

You are given a binary tree. Your task is to check whether the given binary tree is a Complete Binary tree or not.

A Complete Binary tree is a binary tree whose every level, except possibly the last, is completely filled, and all nodes in the last level are placed at the left end.

Example of a complete binary tree :

Design a seat reservation system. seats are numbered from 1 to n.Implement the SeatManager class:SeatManager(int n) Initializes a SeatManager object that will manage n seats numbered from 1 to n. All seats are initially available.int reserve() Fetches the smallest-numbered unreserved seat, reserves it, and returns its number.void unreserved(int seat Number) Unreserved the seat with the given seatNumber

You are given two strings BEGIN and END and an array of strings DICT. Your task is to find the length of the shortest transformation sequence from BEGIN to END such that in every transformation you can change exactly one alphabet and the word formed after each transformation must exist in DICT.

Note:

1. If there is no possible path to change BEGIN to END then just return -1.
2. All the words have the same length and contain only lowercase english alphabets.
3. The beginning word i.e. BEGIN will always be different from the end word i.e. END (BEGIN != END).