def Turan(self, n, r):
        """
        http://en.wikipedia.org/wiki/Tur%C3%A1n_graph
        """
        return 0.5 * (n ** 2 - (n % r) * (n / r + 1) ** 2 - ((n % r) - r) * (n / r) ** 2)
dataset/ETHPy150Open algorhythms/HackerRankAlgorithms/Clique.py/Solution.Turan/swapped operands of `-`