Sha256: e0da08f06ef5fd5ff435cb58730ba5b753870899a3b11744470a70657e8dc676
Contents?: true
Size: 1.01 KB
Versions: 20
Compression:
Stored size: 1.01 KB
Contents
# coding: utf-8
describe Integer, "#mobius" do
# A008683
@seq = [1,-1,-1,0,-1,1,-1,0,0,1,-1,0,-1,1,1,0,-1,0,-1,0,
1,1,-1,0,0,1,0,0,-1,-1,-1,0,1,1,1,0,-1,1,1,0,-1,
-1,-1,0,0,1,-1,0,0,0,1,0,-1,0,1,0,1,1,-1,0,-1,1,0,
0,1,-1,-1,0,1,-1,-1,0,-1,1,0,0,1].to_seq
@seq.each_with_index do |i, n|
it "should return #{i} for #{n}" do
n.succ.mobius.should == i
end
it "should return nil for negative number #{-n}" do
(-n.succ).mobius.should be_nil
end
end
it "returns −1 if n is prime" do
Prime.first(10).each do |n|
n.mobius.should == -1
end
end
# A013929
@seq = [4,8,9,12,16,18,20,24,25,27,28,32,36,40,44,45,48,
49,50,52,54,56,60,63,64,68,72,75,76,80,81,84,88,
90,92,96,98,99,100,104,108,112,116,117,120,121,
124,125,126,128,132,135,136,140,144,147,148,150,
152,153,156,160]
@seq.sample(10).each do |n|
it "should return 0 for non-square-free number #{n}" do
n.mobius.should == 0
end
end
end
Version data entries
20 entries across 20 versions & 1 rubygems