SDE - 1

You have been given an integer array/list 'ARR' of size 'N'. Your task is to return the total number of those subsequences of the array in which all the elements are equal.

A subsequence of a given array is an array generated by deleting some elements of the given array with the order of elements in the subsequence remaining the same as the order of elements in the array.

Note :

As this value might be large, print it modulo 10^9 + 7

You are given an array of N integers and an integer K. For each array element, you are allowed to increase or decrease it by a value k. The task is to minimize the difference between the maximum element and the minimum element after modifications.

Aahad and Harshit always have fun by solving problems. Harshit took a sorted array consisting of distinct integers and rotated it clockwise by an unknown amount. For example, he took a sorted array = [1, 2, 3, 4, 5] and if he rotates it by 2, then the array becomes: [4, 5, 1, 2, 3].

After rotating a sorted array, Aahad needs to answer Q queries asked by Harshit, each of them is described by one integer Q[i]. which Harshit wanted him to search in the array. For each query, if he found it, he had to shout the index of the number, otherwise, he had to shout -1.

For each query, you have to complete the given method where 'key' denotes Q[i]. If the key exists in the array, return the index of the 'key', otherwise, return -1.

Note:

Can you solve each query in O(logN) ?

You are given an array 'arr' of strings, where each string consists of English lowercase letters.

A string chain of 'arr' is defined as:

(1) A sequence of string formed using elements of 'arr'.

(2) Every string in the sequence can be formed by inserting a lowercase English letter into the previous string (except the first string).

Find the length of the longest possible string chain of 'arr'.

Example :

Input: 'arr' = ["x", "xx", "y", "xyx"] 

Output: 3

Explanation:
The longest possible string chain is “x” -> “xx” -> “xyx”.
The length of the given chain is 3, hence the answer is 3.

Tell me about your greatest achievement in college.
What type of person are you: happy-go-lucky or hardworking?
Why did you choose the particular project you worked on? How did you test your project?
Will you be able to learn new things, even if you are not interested in them?