https://www.hackerrank.com/challenges/no-idea
Problem
There is an array of n integers. There are also 2 disjoint sets, A and B, each containing m integers. You like all the integers in set A and dislike all the integers in set B. Your initial happiness is 0. For each i integer in the array, if i ϵ A, you add 1 to your happiness. If i ϵ B, you add -1 to your happiness. Otherwise, your happiness does not change. Output your final happiness at the end.
Note: Since A and B are sets, they have no repeated elements. However, the array might contain duplicate elements.
Input Format
The first line contains integers n and m separated by a space.
The second line contains n integers, the elements of the array.
The third and fourth lines contain m integers, A and B, respectively.
Output Format
Output a single integer, your total happiness.
Sample Input 0
3 2
1 5 3
3 1
5 7
Sample Output 0
1