Sieve of Pritchard: Difference between revisions
→Julia: Started by noticing that the max() should be a min(), then noticed there were some other places that could be made more efficient.
(→Python: Started by noticing that the max() should be a min(), then noticed there was some other places that could be made more efficient.) |
(→Julia: Started by noticing that the max() should be a min(), then noticed there were some other places that could be made more efficient.) |
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=={{header|Julia}}==
{{trans|Raku}}
Added add/remove statistics. "Removed" figure is a combination of composites and primes under sqrt of limit.
Running on Julia 1.0
<syntaxhighlight lang="julia">""" Rosetta Code task rosettacode.org/wiki/Sieve_of_Pritchard """
""" Pritchard sieve of primes up to limit, uses limit for type of the primes """
""" using Julia 1.0 (on Tio.run) """
function pritchard(limit::T) where T <: Integer
members = Set(one(T))
steplength = 1 # wheel size
prime = T(2)
primes = T[]
ac = 2 # added count, since adding 1 & 2 during initialization
rc = 1 # removed count, since 1 will be removed at the end
rtlim = T(floor(sqrt(limit))) # this allows the main loop to go
while prime <= rtlim # one extra time, eliminating the follow-up for
# the last partial wheel (if present)
if steplength < limit
for w in members
n = w + steplength
while n <=
push!(members, n)
n += steplength
end
end
steplength =
end
for w in sort!(collect(members))
if n > nlimit break end
rc += 1
end
if np < prime break end
push!(primes, prime)
# prime = prime == 2 ? 3 : sort!(collect(members))[2]
# this is faster
nlimit = min(steplength *
▲ push!(members, n)
▲ n += steplength
▲ end
▲ end
end
println("up to ",limit, ", added:", ac, " removed:", rc, " prime count:", length(primes) + length(members) )
return sort!(
end
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