[프로그래머스/JAVA] 등차수열의 특정한 항만 더하기

class Solution {
    public int solution(int a, int d, boolean[] included) {
        int answer = 0;
        
        for(int i=1; i<=included.length; i++){
            if(included[i-1]){
                answer += a + d*(i-1);
            }
        }
        
        return answer;
    }
}