SDE - 1

You are given an array consisting of 'N' elements and you need to perform 'Q' queries on the given array. Each query consists of an integer which tells the number of elements by which you need to left rotate the given array. For each query return the final array obtained after performing the left rotations.

Note:

Perform each query on the original array only i.e. every output should be according to the original order of elements.

Example:

Let the array be [1, 2, 3, 4, 5, 6] and the queries be {2, 4, 1}. For every query, we’ll perform the required number of left rotations on the array.

For the first query, rotate the given array to the left by 2 elements, so the resultant array is: [3, 4, 5, 6, 1, 2].

For the second query, rotate the given array to the left by 4 elements, so the resultant array is: [5, 6, 1, 2, 3, 4].

For the third query, rotate the given array to the left by 1 element, so the resultant array is: [2, 3, 4, 5, 6, 1].

Given a singly linked list of integers. Your task is to return the head of the reversed linked list.

For example:

The given linked list is 1 -> 2 -> 3 -> 4-> NULL. Then the reverse linked list is 4 -> 3 -> 2 -> 1 -> NULL and the head of the reversed linked list will be 4.

Follow Up :

Can you solve this problem in O(N) time and O(1) space complexity?

You are given two strings A and B. Find the index of the first occurrence of A in B. If A is not present in B, then return -1.

For Example:

A = “bc”, B = “abcddbc”.
String “A” is present at index 1, and 5(0-based index), but we will return 1 as it is the first occurrence of “A” in string “B”.

Follow Up:

Can you solve this in linear time and space complexity?

You have been given ‘N’ courses and some courses may have prerequisites. Now consider a matrix ‘PREREQUISITES’ of size 'M' x 2 which represents that you must complete the course 'PREREQUISITES[i][1]' before the course 'PREREQUISITES[i][0]'.

Your task is to return the order of courses you should take to finish all courses.

Note:

If it is impossible to finish all courses, return an empty array. If there are multiple answers, return any one.

For example:

Input:
3 2
1 2
2 3

There are three courses to take. To start with, First course 3 is taken. Then course 2 is taken for which course 3 must be completed. 

At last course 1 is taken for which course 2 must be completed. So the correct course order is [3,2,1].    

Given a graph, check whether the graph is bipartite or not. Your function should return true if the given graph's vertices can be divided into two independent sets, ‘U’ and ‘V’ such that every edge (‘u’, ‘v’) either connects a vertex from ‘U’ to ‘V’ or a vertex from ‘V’ to ‘U’.

You are given a 2D array ‘edges’ which contains 0 and 1, where ‘edges[i][j]’ = 1 denotes a bi-directional edge from ‘i’ to ‘j’.

Note:

If edges[i][j] = 1, that implies there is a bi-directional edge between ‘i’ and ‘j’, that means there exists both edges from ‘i’ to ‘j’ and to ‘j’ to ‘i’.

For example

Given:
‘N’ = 3
‘edges’ = [[0, 1, 1], [0, 0, 1], [0,0,0]]. 

You are given a stack ‘S’. Your task is to sort the sack recursively.

Note:

Looping through the stack is not allowed.
You need to return a stack that is sorted in descending order.

For example:

Given stack S = 1 3 2 
The output will be 3 2 1 since it is the sorted order.