Subtract the Product and Sum of Digits of an Integer

给一个数, 返回它的每个位上的数的积和和的差.

class Solution {
    public int subtractProductAndSum(int n) {
        int p = 1;
        int s = 0;
        while(n > 0) {
            p *= n % 10;
            s += n % 10;
            n /= 10;
        }
        return p - s;
    }
}