SDE - Intern

You have been given a string STR. Your task is to find the total number of palindromic substrings of STR.

Example :

If the input string is "abbc", then all the possible palindromic substrings would be: ["a", "b", "b", c", "bb"] and hence, the output will be 5 since we have 5 substrings in total which form a palindrome.

Note :

A string is said to be a 'Palindrome' if it is read the same forwards and backwards. 
For example, “abba” is a palindrome, but “abbc” is not.

A 'Substring' is a contiguous sequence of characters within a string. 
For example, "a", "b", "c", "ab", "bc", "abc" are substrings of "abc".

Given an array of N integers, find the number of ways modulo 1e9+7 to select K integers such that their product is positive integer. The given integers can positive or negative. N <= 1e6, K <= N.

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]]. 

Given a number 'N', you need to find all possible unique ways to represent this number as the sum of positive integers.

Note

1. By unique it is meant that no other composition can be expressed as a permutation of the generated composition. For eg. [1, 2, 1] and [1, 1, 2] are not unique.  

2. You need to print all combinations in non-decreasing order for eg. [1, 2, 1] or [1, 1, 2] will be printed as [1, 1, 2], however, the order of printing all the sequences can be random. 

You have been given an array/list ‘ARR’ of integers consisting of ‘N' integers. You need to rearrange ‘ARR’ so that no two adjacent elements are equal. You may return any valid rearrangement and it is guaranteed the answer exists.

Example :

Let’s say you have an array/list ‘ARR = [1,1,2,2]’. 

Then a valid rearrangement can be [1,2,1,2] or [2,1,2,1] such that no two adjacent elements are equal. [2,1,1,2] is an invalid arrangement because two adjacent elements are equal.