I need help writting java code to compute two polynomial.

I have to design and implement a class for polynomials that uses a
linked list to store the coefficients ( so there is virtually no
limit on n). Include a method that multiplies two polynomial.

for example 2 + x^2 - 3x^3 and 1 - x - 2x^2 + 3x^3

are represented by
2, 0, 1, -3 and 1, -1, ,-2, 3

the product of the two polynomials is

2 - 2x - 3x^2 + 2x^3 + x^4 + 9x^5 - 9x^6
which is represented by
2, -2, -3, 2, 1, 9, -9