SDE - Intern

You are given ‘N’ types of umbrellas, where each umbrella can shelter some number of people. Given the number of people each umbrella can shelter in the array “UMBRELLA”, you need to determine the minimum number of umbrellas required to cover exactly ‘M’ people with umbrellas.

Note -

You have an infinite number of umbrellas of each type.
If it is not possible to shelter exactly ‘M’ people then print -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.