It's worth giving the Wiki page a quick read, it's very accessible: https://en.wikipedia.org/wiki/Radix_sort https://en.wikipedia.org/wiki/Radix_sort TL;DR: I

It's worth giving the Wiki page a quick read, it's very accessible: https://en.wikipedia.org/wiki/Radix_sort https://en.wikipedia.org/wiki/Radix_sort TL;DR: I guess the hash unique approach is technically a radix sort in base-64 if you hash the inputs before applying the radix sort, but a realistic radix sort will use far fewer buckets giving it much better cache locality and won't unnecessarily hash the buckets. Also it's possible to write a radix sort that doesn't use any extra indirection, but that's a much more complex implementation and I doubt it really has any performance benefits.