parity_perftest.jl

using Nemo
using BenchmarkTools

function perm_sample(N=1000, samplesize=10000, seed=1234)
    sample = Nemo.Generic.perm[]
    srand(seed)
    for i in 1:samplesize
        push!(sample, rand(PermutationGroup(N)))
    end
    return sample
end

parity_new(a::Nemo.Generic.perm) = sum([(length(c)+1)%2 for c in cycles(a)])%2

function par()
    for p in perm_sample()
        parity(p)
    end
end
function par_new()
    for p in perm_sample()
        parity_new(p)
    end
end

perms = perm_sample();
@assert parity.(perms) == parity_new.(perms)

par()
orig = @benchmark par()
par_new()
new = @benchmark par_new();

display(orig)
println("")
display(new)
println("")
display(judge(median(new), median(orig)))
println("")