设计一个按照时间抽取的基2快速傅里叶变换（基2FFT-DIT）。输入倒位序，输出自然顺序。-Design is taken in accordance with the time radix-2 fast Fourier transform the (base 2FFT-DIT). Enter the inversion sequence, the output of the natural order.

本程序对输入序列din实现DIT——FFT基2算法，点数取大于等于din长度的2的幂次-The program realization of the input sequence din DIT- FFT radix-2 algorithm, din length greater than or equal points to take a power of 2