A function that compute the max positive product of 3 intergers

max.positive.product.js

/*
Write a function which takes in an array of integers and returns the highest positive product 
possible by multiplying 3 distinct numbers. NO SORTING is ALLOWED 

    example: 

    [1, 3, 5, 2, 8, 0, -1, 3] 

    => 8 * 5 * 3 = 120 

    [0, -1, 3, 100, -70, -5] 

    => -70*-50*100=350000
*/

var a = [1,3,5,2,8,0,-1,3]
//a = [0,-1,3,100,-70,-5]
//a = [3,-3,-3,-3,-3,-3,-1,-3]

function maxPossitiveProduct(a){
    var n = a.length;

    var p3rd = 0, p2nd = 0, p1st = 0;
    var n1st = 0, n2nd = 0;
    var q,u,v;

    for(var i = 0; i < n; i++){
        // possitive cases
        if (a[i] > p1st){
            p3rd = p2nd;
            p2nd = p1st;
            p1st = a[i];
        } else if (a[i] > p2nd && a[i] != p1st){
            p3rd = p2nd;
            p2nd = a[i];
        } else if(a[i] > p3rd && a[i] != p1st && a[i] != p2nd) {
            p3rd = a[i];
        } else 

        // negative cases
        if (a[i] < n1st){
            n2nd = n1st;
            n1st = a[i];
        } else if (a[i] < n2nd && a[i] != n1st) {
            n2nd = a[i];
        }
    }

    if(n1st * n2nd > p2nd * p3rd){
        q = n1st;
        u = n2nd;
        v = p1st;
    } else {
        q = p1st;
        u = p2nd;
        v = p3rd;
    }

    return [q,u,v];
}
r = maxPossitiveProduct(a);

var max = r[0] * r[1] * r[2];
if(max == 0){
    console.log("No result found.");
} else {
    console.log("Max: " + max + " Combination: " + r[0] + " " + r[1] + " " + r[2]);
}