THE GENERAL ALGORITHM OF THE FFT AND ITS MINIMUM
FFT的一般计算式(B型)及其极小化问题

In this paper, we derive the general formula of the FFT algorithm of the radix-M(M=2~n), n being a positive integer, and the time complexity of the FFT algorithm fromtheoretical analysis. The result is consistent with computer computations. Further, we discussthe existence and uniqueness of the minimum of "the radixes numbers of real multiplications"curve, and obtain conclusions disagreeing with Bergland-Brigham's.