jnh@ece-csc.UUCP (Joseph Nathan Hall) (01/19/89)
All the discussion about bit counting has reminded me of an analytically unrelated problem that still sounds similar. Bit-reversed counters are used in FFT algorithms (and probably other things I don't know about). I have occasionally wondered what interesting ways there of implementing bit-reversed counting . . . An example of bit-reversed counting for your edification: Normal Bit-reversed 0001 1 1000 8 0010 2 0100 4 0011 3 1100 12 0100 4 0010 2 0101 5 1010 10 ...etc. In a similar vein, what interesting bit-reversal algorithms are there (distinct from the problem of COUNTING bit-reversed)? I would consider algorithms that don't use tables (or, better, use very small or tricky tables) much more interesting than the obvious brute-force approaches. I will post a summary of anything worthwhile that's mailed to me, but if you have a method of general interest I'd suggest you go ahead and post it yourself (succintly). -- v v sssss|| joseph hall || 201-1D Hampton Lee Court v v s s || jnh@ece-csc.ncsu.edu (Internet) || Cary, NC 27511 v sss || the opinions expressed herein are not necessarily those of my -----------|| employer, north carolina state university . . . . . . . . . . .