G2.sage

load("__common__.sage")

def generator():
    A = matrix([[choice([-1,1])*randrange(1,7) for _ in range(0,4)] for _ in range(0,4)])
    line = randint(1,3)
    indices = choice(([(line,0),(line,1),(line,2),(line,3)],[(0,line),(1,line),(2,line),(3,line)]))
    shuffle(indices)
    A[indices[0]]=0
    A[indices[1]]=0
    A[indices[2]]=choice([-1,1])
    A[indices[3]]=choice([-1,1])*randrange(2,4)
    A[randint(0,3),randint(0,3)]=0

    return {
      "matrix": A,
      "determinant": A.determinant()
    }