void plusMinus(vector arr) { int positive = 0, negative = 0, zero = 0; int n = arr.size();

for (int num : arr) {
    if (num > 0) positive++;
    else if (num < 0) negative++;
    else zero++;
}

cout << fixed << setprecision(6);
cout << (double)positive / n << endl;
cout << (double)negative / n << endl;
cout << (double)zero / n << endl;

}