The mapping algorithm of WgsHnaTyping. A) The mapping algorithm searches twice for candidates reads. First time, the searching is performed from the 5′ end to the 3 end and then again from right to left. B) For mapping from the 5′ end, the prefixes of reads are used as the index key. C) For mapping from the 3′ end, the postfixes of reads are used as the index key.