Associate Professional

You have been given an integer array/list(ARR) of size 'N'. It only contains 0s, 1s and 2s. Write a solution to sort this array/list.

Note :

Try to solve the problem in 'Single Scan'. ' Single Scan' refers to iterating over the array/list just once or to put it in other words, you will be visiting each element in the array/list just once.

You are given the 'head' of a singly linked list. Your task is to group all the nodes with odd indices together followed by the nodes with even indices, and return the reordered list’s head.

The first node is considered odd, and the second node is even, and so on.

Note:

Keep in mind that reordering is to be done according to the indexes and not the node values.
Also, ensure that the relative order inside both the even and odd groups should remain as it was in the input.

Example:

Input: 'head' -> 1 -> 3 -> 5 -> 7

Output: 'head' -> 1 -> 5 -> 3 -> 7

Explanation:
The nodes with odd indices (1, 5) are grouped together, followed by the nodes with even indices (3, 7).

You are given an array consisting of 'N' positive integers where each integer is either 0 or 1 or 2. Your task is to sort the given array in non-decreasing order.

Note :

1. The array consists of only 3 distinct integers 0, 1, 2.
2. The array is non-empty.

Given two 1-dimensional arrays containing strings of lowercase alphabets, print the elements that are common in both the arrays i.e. the strings that are present in both the arrays.

Note:

An element of one array can be mapped only to one element of the array. For example :

Array 1 = {“ab”, “dc”, “ab”, “ab”}
Array 2 = {“dc”, “ab”, “ab”} 

The common elements for the above example will be “dc”, “ab”, and “ab”.