中文说明：
用C或者matlab编写基2 FFT快速算法，输入点数是2的幂次方，序列视作既包含实部也包含虚部。要求一个函数计可以做正变换，也可以做反变换。编写输入序列，先进行正反向变换，得到离散频谱，再将离散频谱加载到输入端进行验证，从输出端获取序列，和原来的序列进行比较，看看是否相等。序列可随意设为2的幂次项！
English Description：
Use C or matlab to write the fast algorithm of radix-2 FFT. The number of input points is the power of 2, and the sequence is regarded as containing both real and imaginary parts. It is required that a function meter can do positive transformation or inverse transformation. Write the input sequence, first perform forward and reverse transformation to obtain the discrete spectrum, then load the discrete spectrum to the input for verification, obtain the sequence from the output, and compare it with the original sequence to see whether it is equal. The sequence can be set to the power of 2 at will