Chessboard CountInRank Failing Assertions

Exercism
1

I’m working on the Chessboard exercise, and I’ve gotten all the methods working except for CountInRank.

// CountInRank returns how many squares are occupied in the chessboard,
// within the given rank.
func CountInRank(cb Chessboard, rank int) int {
	var num_occupied int = 0
    if rank < 1 || rank > 8 {
        return 0
    } else {
    	for i, _ := range cb {
            if cb[i][rank] == true {
                num_occupied += 1
            }
        }
        return num_occupied
    }
}

This seems to me like it should hit all the files of the rank, and it seems to, but the returned counts are not matching the expected results.

2

Would this solution work to count, say, the first/left most rank?

3

I don’t see why it wouldn’t; I am only allowing ranks between 1 and 8 to be calculated through iteration, per the test case instructions.

4

What index gives the first rank?

5

Per the test cases, it looks like ranks 1-8 should have nonzero results, so 1 should give the first rank.

6

What number needs to be used for rank to get the left most rank? I’m looking for a single number as the answer :slightly_smiling_face:

7

The left most rank would be 1.

8

So we’d do something like this to print the first element (5) of the array? You may want to check what this code prints.

func main() {
	data := []int{5, 10, 15, 20}
	fmt.Println(data[1])
}
9

Ah, I figured it out. While the left most rank is 1, the left most array index is 0, so I had to do a rank - 1 during the iteration. Thank you for the help!

1 Like