Sha256: 58d6ae9f3c6fb2af13533a781d460a69024f47d4d3b0293599a8293ef30a0046
Contents?: true
Size: 1.03 KB
Versions: 16
Compression:
Stored size: 1.03 KB
Contents
describe Integer, "#economical?" do
# http://www.research.att.com/~njas/sequences/A046759
FRUGAL = [125,128,243,256,343,512,625,729,1024,1029,1215,
1250,1280,1331,1369,1458,1536,1681,1701,1715,1792,
1849,1875,2048,2187,2197,2209,2401,2560,2809,3125,
3481,3584,3645,3721,4096,4374,4375,4489,4802,
4913]
# http://www.research.att.com/~njas/sequences/A046758
EQUIDIGITAL = [1,2,3,5,7,10,11,13,14,15,16,17,19,21,23,25,27,29,
31,32,35,37,41,43,47,49,53,59,61,64,67,71,73,79,
81,83,89,97,101,103,105,106,107,109,111,112,113,
115,118,119,121,122,123,127,129,131,133,134,135,
137,139]
ECONOMICAL = EQUIDIGITAL + FRUGAL
it "returns true for economical numbers" do
ECONOMICAL.each do |number|
number.should be_economical
end
end
it "returns false for non-economical numbers" do
(((1..139).to_a - EQUIDIGITAL - FRUGAL)).each do |number|
number.should_not be_economical
end
end
end
Version data entries
16 entries across 16 versions & 1 rubygems