public static int eval(int n, int a, int x) {
        int res = 0;
        for (int i = n; i >= 0; i--) {
            res = (res * x) + a;
        }
        return res;
    }
Write a program that can evaluate a polynomial
p(x) = ao + a1x^1 + a2x^2 + .... + anx^n
<p>
https://en.wikipedia.org/wiki/Horner%27s_method
java8/src/main/java/com/shekhargulati/random/algebra/RandomProblem005.java