def sqnorm(v):
    """
    Compute the squared euclidean norm of the vector v.

    Input:
    v           A vector of polynomials

    Output:
    res         The squared euclidean norm of v

    Format:     Coefficient
    """
    res = 0
    for elt in v:
        for coef in elt:
            res += coef ** 2
    return res