Finding factors of a given integer

Question

I have something like this down:

int f = 120;
for(int ff = 1; ff <= f; ff++){
    while (f % ff != 0){            
}

Is there anything w

Answer 1

public class Solution {
    public ArrayList allFactors(int a) {

        int upperlimit = (int)(Math.sqrt(a));
        ArrayList factors = new ArrayList();
        for(int i=1;i <= upperlimit; i+= 1){
            if(a%i == 0){
                factors.add(i);
                if(i != a/i){
                    factors.add(a/i);
                }
            }
        }
        Collections.sort(factors);
        return factors;
    }
}

The above solution simply works like calculating prime factors. The difference being for every prime factor we keep calculating the other part of the product i.e the reqd number.