算法图解:
http://baike.baidu.com/link?url=hGNkWIOLRJ_LDWMJRECxCPKUw7pI3s8AH5kj-944RwgeBSa9hGpTaIz5aWYsl_sTyBgjxW-CnXn9LEHcy4GJE6N71Z7guFriwOVGLjGOFeaI44gRVid1N8iL-li-7wOt5WoH4K9zOTNFeeTB31HBOq
实现代码:
http://blog.csdn.net/tingting256/article/details/50471033