SDE - 1

You have been given a permutation of ‘N’ integers. A sequence of ‘N’ integers is called a permutation if it contains all integers from 1 to ‘N’ exactly once. Your task is to rearrange the numbers and generate the lexicographically next greater permutation.

To determine which of the two permutations is lexicographically smaller, we compare their first elements of both permutations. If they are equal — compare the second, and so on. If we have two permutations X and Y, then X is lexicographically smaller if X[i] < Y[i], where ‘i’ is the first index in which the permutations X and Y differ.

For example, [2, 1, 3, 4] is lexicographically smaller than [2, 1, 4, 3].

You are given two binary trees with 'n' and 'm' nodes respectively.

You need to return true if the two trees are identical. Otherwise, return false.

Example:

For the trees given below:- 

The given trees are identical as:-
1. The number of nodes in both trees is the same. 
2. The number of edges in both trees is the same. 
3. The data for root for both the trees is the same i.e 5. 
4. The data of root -> left (root’s left child) for both the trees is the same i.e 2.
5. The data of root -> right (root’s right child) for both the trees is the same i.e 3.
6. The data of root -> right -> left ( left child of root’s right child) for both the trees is the same i.e 6.
7. Nodes with data 2 and 6 are the leaf nodes for both the binary trees. 

You are given an array of integers ‘A’ having ‘N’ number of elements. It is given that all the numbers in the array occur twice except the two numbers that appear only one time. You need to find those two non-repeating numbers.

For Example:

If the given array is [ 4, 7, 3, 2, 7, 2 ], you have to find ‘4’ and ‘3’ as 4 and 3 occur one time, and the rest of the elements ( 7 and 2 ) are occurring twice.

You are given an array 'a' of size 'n'.

Print the Next Greater Element(NGE) for every element.

The Next Greater Element for an element 'x' is the first element on the right side of 'x' in the array, which is greater than 'x'.

If no greater elements exist to the right of 'x', consider the next greater element as -1.

For example:

Input: 'a' = [7, 12, 1, 20]

Output: NGE = [12, 20, 20, -1]

Explanation: For the given array,

- The next greater element for 7 is 12.

- The next greater element for 12 is 20. 

- The next greater element for 1 is 20. 

- There is no greater element for 20 on the right side. So we consider NGE as -1.

You are given a starting position for a rat which is stuck in a maze at an initial point (0, 0) (the maze can be thought of as a 2-dimensional plane). The maze would be given in the form of a square matrix of order 'N' * 'N' where the cells with value 0 represent the maze’s blocked locations while value 1 is the open/available path that the rat can take to reach its destination. The rat's destination is at ('N' - 1, 'N' - 1). Your task is to find all the possible paths that the rat can take to reach from source to destination in the maze. The possible directions that it can take to move in the maze are 'U'(up) i.e. (x, y - 1) , 'D'(down) i.e. (x, y + 1) , 'L' (left) i.e. (x - 1, y), 'R' (right) i.e. (x + 1, y).

Note:

Here, sorted paths mean that the expected output should be in alphabetical order.

For Example:

Given a square matrix of size 4*4 (i.e. here 'N' = 4):
1 0 0 0
1 1 0 0
1 1 0 0
0 1 1 1 
Expected Output:
DDRDRR DRDDRR 
i.e. Path-1: DDRDRR and Path-2: DRDDRR

The rat can reach the destination at (3, 3) from (0, 0) by two paths, i.e. DRDDRR and DDRDRR when printed in sorted order, we get DDRDRR DRDDRR.

You are given a Singly Linked List of integers and a reference to the node to be deleted. Every node of the Linked List has a unique value written on it. Your task is to delete that node from the linked list.

A singly linked list is a linear data structure in which we can traverse only in one direction i.e. from Head to Tail. It consists of several nodes where each node contains some data and a reference to the next node.

Note:

• The reference to the head of the linked list is not given.
• The node to be deleted is not a tail node.
• The value of each node in the Linked List is unique.
• It is guaranteed that the node to be deleted is present in the linked list.

A sample Linked List-