Kata

A new school year is approaching, which also means students will be taking tests.

The tests in this kata are to be graded in different ways. A certain number of points will be given for each correct answer and a certain number of points will be deducted for each incorrect answer. For ommitted answers, points will either be awarded, deducted, or no points will be given at all.

Return the number of points someone has scored on varying tests of different lengths.

The given parameters will be:

• An array containing a series of 0s, 1s, and 2s, where 0 is a correct answer, 1 is an omitted answer, and 2 is an incorrect answer.
• The points awarded for correct answers
• The points awarded for ommitted answers (note that this may be negative)
• The points deducted for incorrect answers (hint: this value has to be subtracted)

Note: The input will always be valid (an array and three numbers)

Examples

#1:

[0, 0, 0, 0, 2, 1, 0], 2, 0, 1  -->  9

because:

• 5 correct answers: 5*2 = 10
• 1 omitted answer: 1*0 = 0
• 1 wrong answer: 1*1 = 1

which is: 10 + 0 - 1 = 9

#2:

[0, 1, 0, 0, 2, 1, 0, 2, 2, 1], 3, -1, 2)  -->  3

because: 4*3 + 3*-1 - 3*2 = 3