Solution
#include<iostream>
using namespace std;
void plusMinus(vector<int> arr) {
float positives = 0, negatives = 0, zeroes = 0;
int n = arr.size();
for (int i = 0; i < n; i++) {
zeroes += (arr[i] == 0);
positives += (arr[i] > 0);
negatives += (arr[i] < 0);
}
zeroes = zeroes / (double)n;
positives = positives / (double)n;
negatives = negatives / (double)n;
printf("%0.06lf\n%0.06lf\n%0.06lf\n", positives, negatives, zeroes);
}