SDE - 1

Ninja is developing robotics delivery. They have a robot standing at the top left corner(0,0) of the matrix of size N*N. It has to deliver the parcel to the given (x,y) coordinate. There are also obstacles at random points in the matrix. The robot cannot enter the coordinate with an obstacle. It can only travel only on flat coordinates. The obstacle is denoted by 0 and the flat is denoted by 1. Matrix[ x ] [ y ] is denoted by 5. You have to return true if it is possible to deliver the package to the given coordinate Else return false. Given robot can move downwards and rightwards from the given coordinate and cannot enter over the obstacle and cannot move outside the matrix. Matrix[ 0 ][ 0 ] is always 1.

For Example :

Corresponding to the given matrix:-

From (0,0) coordinate robot cannot move to (0,1) 
coordinate since there is obstacle on it.
So to reach (2,2) The path is (0,0) then to (1,0) then to 
(2,0) then to (2,1) and finally (2,2).

You are given an arbitrary array ‘arr’ consisting of N non-negative integers, where every element appears thrice except one. You need to find the element that appears only once.

You are given a class named as BSTIterator that represents an iterator over inorder traversal of a binary search tree. You need to implement the following things as follows:

1. BSTIterator(Node root) - It is a parameterized constructor in which you are given the root of the Binary search tree. It will be called whenever an object of BSTIterator is created.

2. next() - This member function will return the next element in the in-order traversal of the binary search tree. You need to implement this function.

3. hasNext() - This function will return true if there exists the next element in the traversal else it will return false. You need to implement this function

4. prev() - This member function will return the previous element in the in-order traversal of the binary search tree. You need to implement this function.

5. hasPrev() - This function will return true if there exists the previous element in the traversal else it will return false. You need to implement this function

The binary search tree has ‘N’ nodes and you need to print the inorder traversal of the tree using the iterator.

Given a binary tree and the value of two nodes, find the distance between the given two nodes of the Binary Tree.

Distance between two nodes is defined as the minimum number of edges in the path from one node to another.