SDE - Intern

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) ?

What are ACID properties? (Learn)

Design a data structure that satisfies the constraints of a Least Recently Used (LRU).

1. Get(int num): If the key exists, it will return the value of the key stored. Else, return -1.    
2. Put(int key, int value): If the key already exists, update the value of the key. Else add the key-value pair to the cache. If the number of keys is more than the capacity for this operation, delete the least recently key used. 

Example:

For the following input: 

4 2
2 1 4
1 1
1 4

We will initialize an empty LRU cache for the first operation with a maximum capacity of 2.
For the first operation, we need to add a key-value pair (1,4) to the cache.
For the second operation, we need to return the value stored for key 1, i.e., 4
For the third operation, we need to return -1, as we don't have any key 4 in the cache.

So, the final output will be: 
4  -1

Prateek is a kindergarten teacher. He wants to give some candies to the children in his class. All the children stand in a line and each of them has a grade according to his or her performance in the class. Prateek wants to give at least one candy to each child. If two children are standing adjacent to each other, then the one with the higher rating must get more candies than the other. Prateek wants to minimize the total number of candies he must buy.

Given an array 'STUDENTS' of size 'N' that contains the grades for each student, your task is to find what is the minimum number of candies Prateek must buy so that he can distribute them among his students according to the criteria given above.

Example :

Given students' ratings : [5, 8, 1, 5, 9, 4]. 
He gives the students candy in the following minimal amounts : [1, 2, 1, 2, 3, 1]. He must buy a minimum of 10 candies.

Note :

1. If two students having the same grade are standing next to each other, they may receive the same number of candies.
2. Every student must get at least a candy.