plus_minus.js

function main() {
    var n = parseInt(readLine());
    arr = readLine().split(' ');
    arr = arr.map(Number);
    
    let positive = negative = zero = 0;
    for (i =0; i < n; i++){
        let current = arr[i];
        if (current > 0) {
            positive += 1;
        } else if (current < 0) {
            negative += 1;
        } else {
            zero += 1;
        }
    }
    console.log((positive / n).toFixed(6));
    console.log((negative / n).toFixed(6));
    console.log((zero / n).toFixed(6));

}