This commit is contained in:
Ingy döt Net 2013-04-10 21:29:02 -07:00
parent 764da6cbbb
commit db842d013d
19005 changed files with 197040 additions and 7 deletions

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link hexcvt,printf
procedure main()
s := "The quick brown fox jumps over the lazy dog"
a := "414FA339"
printf("crc(%i)=%s - implementation is %s\n",
s,r := crc32(s),if r == a then "correct" else "in error")
end
procedure crc32(s) #: return crc-32 (ISO 3309, ITU-T V.42, Gzip, PNG) of s
static crcL,mask
initial {
crcL := list(256) # crc table
p := [0,1,2,4,5,7,8,10,11,12,16,22,23,26] # polynomial terms
mask := 2^32-1 # word size mask
every (poly := 0) := ior(poly,ishift(1,31-p[1 to *p]))
every c := n := 0 to *crcL-1 do { # table
every 1 to 8 do
c := iand(mask,
if iand(c,1) = 1 then
ixor(poly,ishift(c,-1))
else
ishift(c,-1)
)
crcL[n+1] := c
}
}
crc := ixor(0,mask) # invert bits
every crc := iand(mask,
ixor(crcL[iand(255,ixor(crc,ord(!s)))+1],ishift(crc,-8)))
return hexstring(ixor(crc,mask)) # return hexstring
end

2
Task/CRC-32/J/crc-32-1.j Normal file
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((i.32) e. 32 26 23 22 16 12 11 10 8 7 5 4 2 1 0) 128!:3 'The quick brown fox jumps over the lazy dog'
_3199229127

5
Task/CRC-32/J/crc-32-2.j Normal file
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(2^32x)|((i.32) e. 32 26 23 22 16 12 11 10 8 7 5 4 2 1 0) 128!:3 'The quick brown fox jumps over the lazy dog'
1095738169
require'convert'
hfd (2^32x)|((i.32) e. 32 26 23 22 16 12 11 10 8 7 5 4 2 1 0) 128!:3 'The quick brown fox jumps over the lazy dog'
414FA339

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IntegerString[Hash["The quick brown fox jumps over the lazy dog", "CRC32"], 16, 8]
-> "414fa339"