Plus Minus

Given an array of integers, calculate the fractions of its elements that are positive, negative, and are zeros. Print the decimal value of each fraction on a new line.

Note: This challenge introduces precision problems. The test cases are scaled to six decimal places, though answers with absolute error of up to 10^-4 are acceptable.

For example, given the array arr = [1, 1, 0, -1, -1] there are 5 elements, two positive, two negative and one zero. Their ratios would be
. It should be printed as

1
2
3

0.400000
0.400000
0.200000

Function Description

Complete the plusMinus function in the editor below. It should print out the ratio of positive, negative and zero items in the array, each on a separate line rounded to six decimals.

plusMinus has the following parameter(s):

• arr: an array of integers

Input Format

The first line contains an integer, n, denoting the size of the array.
The second line contains n space-separated integers describing an array of numbers .
arr(arr[0], arr[1], arr[2],…arr[n - 1])

Constraints

0 < n <= 100
-100 <= arr[i] <= 100

Output Format

You must print the following 3 lines:

1. A decimal representing of the fraction of positive numbers in the array compared to its size.
2. A decimal representing of the fraction of negative numbers in the array compared to its size.
3. A decimal representing of the fraction of zeros in the array compared to its size.

Sample Input

1
2

6
-4 3 -9 0 4 1

Sample Output

1
2
3

0.500000
0.333333
0.166667

Explanation

There are 3 positive numbers, 2 negative numbers, and 1 zero in the array.

The proportions of occurrence are positive: , negative: and zeros: .

Solution

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

// Complete the plusMinus function below.
function plusMinus(arr) {
    let totalCount = (arr || []).length;
    let { posNum, negNum, zeroNum } = (arr || []).reduce((target, item) => {
        !item
            ? target['zeroNum']++
            :
            (item > 0
                ? target['posNum']++
                : target['negNum']++
            );

        return target;
    }, { zeroNum: 0, posNum: 0, negNum: 0 });

    console.log(`${posNum / totalCount}\n${negNum / totalCount}\n${zeroNum / totalCount}`);
}