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Weird numbers: Difference between revisions
Crystal code
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{{out}}
<pre>The first 25 weird numbers:70 836 4030 5830 7192 7912 9272 10430 10570 10792 10990 11410 11690 12110 12530 12670 13370 13510 13790 13930 14770 15610 15890 16030 16310</pre>
=={{header|Crystal}}==
{{trans|Go}}
<lang ruby>def divisors(n : Int32) : Array(Int32)
divs = [1]
divs2 = [] of Int32
i = 2
while i * i < n
if n % i == 0
j = n // i
divs << i
if i != j
divs2 << j
end
end
i += 1
end
i = divs.size - 1
# TODO: Use reverse
while i >= 0
divs2 << divs[i]
i -= 1
end
divs2
end
def abundant(n : Int32, divs : Array(Int32)) : Bool
divs.sum > n
end
def semiperfect(n : Int32, divs : Array(Int32)) : Bool
if divs.size > 0
h = divs[0]
t = divs[1..]
return n < h ? semiperfect(n, t) : n == h || semiperfect(n - h, t) || semiperfect(n, t)
end
return false
end
def sieve(limit : Int32) : Array(Bool)
# false denotes abundant and not semi-perfect.
# Only interested in even numbers >= 2
w = Array(Bool).new(limit, false) # An array filled with 'false'
i = 2
while i < limit
if !w[i]
divs = divisors i
if !abundant(i, divs)
w[i] = true
elsif semiperfect(i, divs)
j = i
while j < limit
w[j] = true
j += i
end
end
end
i += 2
end
w
end
def main
w = sieve 17000
count = 0
max = 25
print "The first 25 weird numbers are: "
n = 2
while count < max
if !w[n]
print "#{n} "
count += 1
end
n += 2
end
puts "\n"
end
require "benchmark"
puts Benchmark.measure { main }
</lang>
{{out}}
<pre>
The first 25 weird numbers are: 70 836 4030 5830 7192 7912 9272 10430 10570 10792 10990 11410 11690 12110 12530 12670 13370 13510 13790 13930 14770 15610 15890 16030 16310
# Benchmark with --release flag
0.046875 0.000000 0.046875 ( 0.040754)
</pre>
=={{header|D}}==
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