SDE - Intern

Ninja is a boy who lives in ninjaland. Every day, during the morning he gets 1 coin from his mother. He wants to buy exactly ‘N’ candies. Each of the candies cost 2 coins usually and 1 coin if it is on sale. Ninja has to buy exactly K[i] candies of the i-th type(he buys candies in the evening).

Ninjas can buy any(possibly zero) number of candies of any type during any day(if he has enough money to do it). If the candy is on sale he can buy it for 1 coin and otherwise he has to buy it for 2 coins.

There are ‘M’ special offers in the candy shop. The j-th offer (D[j], C[j]) means that candies of the C[j]-th type are on sale during the D[j]-th day.

Ninja wants to buy all candies as soon as possible. Your task is to calculate the minimum day when he can buy all the candies.

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. 

Who is your role model.

Tell me about yourself.