用java编写的用蝶式算法实现的fft,用来计算两个多项式的乘积,输入文件的格式如压缩包中的data5.txt,结果输出到result.txt中。-java prepared with the use of the butterfly fft algorithm, used to calculate the product of two polynomials. input file formats such as compressed data5.txt the results were exported to result.txt.