Smarandache prime-digital sequence: Difference between revisions
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→{{header|Phix}}: %V->%v, missing commas in fmts, plus it's gotten a touch slower somehow.
(Added solution for Action!) |
m (→{{header|Phix}}: %V->%v, missing commas in fmts, plus it's gotten a touch slower somehow.) |
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Line 1,468:
if they ended in 2 or 5), which we efficiently achieve by alternately adding {4,-4}. Digits to the left
of that must all be 2/3/5/7, so we add {1,2,2,-5}*10^k to cycle round those digits.
Otherwise it is exactly like counting by adding 1 to each digit and carrying 1 left when we do a 9->0
or in this case 7->2|3.
I had planned to effectively merge a list of potential candidates with a list of all prime numbers,
Line 1,512 ⟶ 1,513:
<span style="color: #000000;">populate_spds</span><span style="color: #0000FF;">(</span><span style="color: #000000;">25</span><span style="color: #0000FF;">)</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;">"spds[1..25]:%
<span style="color: #008080;">for</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">to</span> <span style="color: #000000;">5</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">p</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">10</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">populate_spds</span><span style="color: #0000FF;">(</span><span style="color: #000000;">p</span><span style="color: #0000FF;">)</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;">"spds[%,d]:%,d\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">p</span><span style="color: #0000FF;">,</span><span style="color: #000000;">spds</span><span style="color: #0000FF;">[</span><span style="color: #000000;">p</span><span style="color: #0000FF;">]})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">7</span> <span style="color: #008080;">to</span> <span style="color: #000000;">10</span> <span style="color: #008080;">do</span>
Line 1,536 ⟶ 1,537:
largest spds prime less than 1,000,000,000: 777,777,773
largest spds prime less than 10,000,000,000: 7,777,777,577
"
</pre>
For comparison, on the same machine:<br>
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