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Sequence: smallest number greater than previous term with exactly n divisors: Difference between revisions

m
→‎{{header|Phix}}: syntax coloured
(Added Quackery optimised version)
m (→‎{{header|Phix}}: syntax coloured)
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=={{header|Phix}}==
Uses the optimisation trick from pascal, of n:=power(2,next-1) when next is a prime>4.
<!--<lang Phix>constant limit = 15(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
sequence res = repeat(0,limit)
<span style="color: #008080;">constant</span> <span style="color: #000000;">limit</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">15</span>
integer next = 1
<span style="color: #004080;">sequence</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">limit</span><span style="color: #0000FF;">)</span>
atom n = 1
<span style="color: #004080;">integer</span> <span style="color: #000000;">next</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
while next<=limit do
<span style="color: #004080;">atom</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
integer k = length(factors(n,1))
<span style="color: #008080;">while</span> <span style="color: #000000;">next</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">limit</span> <span style="color: #008080;">do</span>
if k=next then
<span style="color: #004080;">integer</span> <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">factors</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">))</span>
res[k] = n
<span style="color: #008080;">if</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">=</span><span style="color: #000000;">next</span> <span style="color: #008080;">then</span>
next += 1
<span style="color: #000000;">res</span><span style="color: #0000FF;">[</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">n</span>
if next>4 and is_prime(next) then
<span style="color: #000000;">next</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
n := power(2,next-1)-1 -- (-1 for +=1 next)
<span style="color: #008080;">if</span> <span style="color: #000000;">next</span><span style="color: #0000FF;">></span><span style="color: #000000;">4</span> <span style="color: #008080;">and</span> <span style="color: #7060A8;">is_prime</span><span style="color: #0000FF;">(</span><span style="color: #000000;">next</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
end if
<span style="color: #000000;">n</span> <span style="color: #0000FF;">:=</span> <span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">next</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">1</span> <span style="color: #000080;font-style:italic;">-- (-1 for +=1 next)</span>
end if
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
n += 1
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end while
<span style="color: #000000;">n</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
printf(1,"The first %d terms are: %v\n",{limit,res})</lang>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"The first %d terms are: %v\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">limit</span><span style="color: #0000FF;">,</span><span style="color: #000000;">res</span><span style="color: #0000FF;">})</span>
<!--</lang>-->
{{out}}
<pre>
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