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乘法快速运算？如果你的n长度小于600（二进制），就最好不要考虑乘法的分治算法。对于快速乘法，可以考虑使用快速傅立叶变换来做。

Posted by 411465294 at 2007-12-02 16:31:01 on Problem 3324 and last updated at 2007-12-02 16:35:00
In Reply To:求教：我的乘法基为2^32,直接相乘，太耗时了,该如何优化？ Posted by:WMM_205 at 2007-12-02 14:32:38

Followed by:

用FFT写了个大数乘法，本机测试比直接相乘效果还差，拜托大牛们给点想法， (0) WMM_205 2007-12-02 21:04:08
- 据我搜索资料，发现最快的就是FFT了。也许你的算法效率问题不在那儿~ 呵呵~~纯属猜测。期待牛人回复~~ (0) 411465294 2007-12-02 22:44:00
  - 改进乘法复杂度的常数因子（乘法计算减少一半），还是无法过，期待指点，，， (619) WMM_205 2007-12-03 16:50:23
  - Re:据我搜索资料，发现最快的就是FFT了。也许你的算法效率问题不在那儿~ 呵呵~~纯属猜测。期待牛人回复~~ (0) yygy 2014-08-05 23:41:45
- n * log(n) ? (0) LiZhiXu 2007-12-03 17:00:09
  - O(n^2) (0) WMM_205 2007-12-03 17:03:19
    - O(n^2)那还不如直接搞……写个n * log(n)的吧，不过貌似这题用不上…… (0) LiZhiXu 2007-12-03 17:10:07

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