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Distribution of 0 digits in factorial series: Difference between revisions

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Distribution of 0 digits in factorial series (view source)

Revision as of 20:30, 13 June 2021

23,021 bytes added ,  2 years ago
→‎{{header|Phix}}
m (→‎{{header|Pascal}}: delete unused arrays, reorder, more comments)
Line 389:
First ratio < 0.16 47332 0.15999999579985665
Real time: 4.898 s CPU share: 99.55 % // 2.67s on 2200G freepascal 3.2.2</pre>
 
=={{header|Phix}}==
Using "string math" to create reversed factorials, for slightly easier skipping of "trailing" zeroes,
but converted to base 1000 and with the zero counting idea from Pascal, which sped it up threefold.
<!--<lang Phix>(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">rfs</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- reverse factorial(1) in base 1000</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">init_zc</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">zc</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;">999</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">9</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">zc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2</span> <span style="color: #000080;font-style:italic;">-- 00x</span>
<span style="color: #000000;">zc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">10</span><span style="color: #0000FF;">*</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2</span> <span style="color: #000080;font-style:italic;">-- 0x0</span>
<span style="color: #000000;">zc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">100</span><span style="color: #0000FF;">*</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2</span> <span style="color: #000080;font-style:italic;">-- x00</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">10</span> <span style="color: #008080;">to</span> <span style="color: #000000;">90</span> <span style="color: #008080;">by</span> <span style="color: #000000;">10</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">zc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> <span style="color: #000080;font-style:italic;">-- 0yx</span>
<span style="color: #000000;">zc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">10</span><span style="color: #0000FF;">*</span><span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> <span style="color: #000080;font-style:italic;">-- y0x</span>
<span style="color: #000000;">zc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">10</span><span style="color: #0000FF;">*(</span><span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">x</span><span style="color: #0000FF;">)]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> <span style="color: #000080;font-style:italic;">-- yx0</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">zc</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">zc</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">init_zc</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">t0</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">time</span><span style="color: #0000FF;">(),</span>
<span style="color: #000000;">total</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">trail</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">first</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">f</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">to</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()=</span><span style="color: #004600;">JS</span><span style="color: #0000FF;">?</span><span style="color: #000000;">10000</span><span style="color: #0000FF;">:</span><span style="color: #000000;">50000</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">carry</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">d999</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">zeroes</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">trail</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">j</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">trail</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rfs</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">while</span> <span style="color: #000000;">j</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">l</span> <span style="color: #008080;">or</span> <span style="color: #000000;">carry</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">j</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">l</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">carry</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">rfs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">])*</span><span style="color: #000000;">f</span><span style="color: #0000FF;">+</span><span style="color: #000000;">carry</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">d999</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">carry</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1000</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">j</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">l</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">rfs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">d999</span>
<span style="color: #008080;">else</span>
<span style="color: #000000;">rfs</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">d999</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">zeroes</span> <span style="color: #0000FF;">+=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d999</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">?</span><span style="color: #000000;">3</span><span style="color: #0000FF;">:</span><span style="color: #000000;">zc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">d999</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">carry</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">carry</span><span style="color: #0000FF;">/</span><span style="color: #000000;">1000</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">j</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #008080;">while</span> <span style="color: #000000;">rfs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">trail</span><span style="color: #0000FF;">]=</span><span style="color: #000000;">0</span> <span style="color: #008080;">do</span> <span style="color: #000000;">trail</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span> <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #000080;font-style:italic;">-- d999 := quick correction for length and zeroes:</span>
<span style="color: #000000;">d999</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">rfs</span><span style="color: #0000FF;">[$]</span>
<span style="color: #000000;">d999</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d999</span><span style="color: #0000FF;"><</span><span style="color: #000000;">100</span><span style="color: #0000FF;">?</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d999</span><span style="color: #0000FF;"><</span><span style="color: #000000;">10</span><span style="color: #0000FF;">?</span><span style="color: #000000;">2</span><span style="color: #0000FF;">:</span><span style="color: #000000;">1</span><span style="color: #0000FF;">):</span><span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zeroes</span> <span style="color: #0000FF;">-=</span> <span style="color: #000000;">d999</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">digits</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rfs</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">3</span><span style="color: #0000FF;">-</span><span style="color: #000000;">d999</span>
<span style="color: #000000;">total</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">zeroes</span><span style="color: #0000FF;">/</span><span style="color: #000000;">digits</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">ratio</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">total</span><span style="color: #0000FF;">/</span><span style="color: #000000;">f</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">ratio</span><span style="color: #0000FF;">>=</span><span style="color: #000000;">0.16</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">first</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">first</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">first</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">f</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">100</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1000</span><span style="color: #0000FF;">,</span><span style="color: #000000;">10000</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">then</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">e</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">elapsed</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">time</span><span style="color: #0000FF;">()-</span><span style="color: #000000;">t0</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;">"Mean proportion of zero digits in factorials to %d is %.10f (%s)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ratio</span><span style="color: #0000FF;">,</span><span style="color: #000000;">e</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()!=</span><span style="color: #004600;">JS</span> <span style="color: #008080;">then</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">e</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">elapsed</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">time</span><span style="color: #0000FF;">()-</span><span style="color: #000000;">t0</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;">"The mean proportion dips permanently below 0.16 at %d. (%s)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">first</span><span style="color: #0000FF;">,</span><span style="color: #000000;">e</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<!--</lang>-->
{{out}}
<pre>
Mean proportion of zero digits in factorials to 100 is 0.2467531862 (0s)
Mean proportion of zero digits in factorials to 1000 is 0.2035445511 (0.2s)
Mean proportion of zero digits in factorials to 10000 is 0.1730038482 (2.3s)
The mean proportion dips permanently below 0.16 at 47332. (1 minute and 2s)
</pre>
=== trailing zeroes only ===
Should you only be interested in the ratio of trailing zeroes, you can do that much faster:
<!--<lang Phix>(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">t0</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">time</span><span style="color: #0000FF;">(),</span>
<span style="color: #000000;">f10</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">log10</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">total</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">first</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">f</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">to</span> <span style="color: #000000;">50000</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">f10</span> <span style="color: #0000FF;">+=</span> <span style="color: #7060A8;">log10</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">digits</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">ceil</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f10</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">zeroes</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">v</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">5</span>
<span style="color: #008080;">while</span> <span style="color: #000000;">v</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">f</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">zeroes</span> <span style="color: #0000FF;">+=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f</span><span style="color: #0000FF;">/</span><span style="color: #000000;">v</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">v</span> <span style="color: #0000FF;">*=</span> <span style="color: #000000;">5</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #000000;">total</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">zeroes</span><span style="color: #0000FF;">/</span><span style="color: #000000;">digits</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">ratio</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">total</span><span style="color: #0000FF;">/</span><span style="color: #000000;">f</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">ratio</span><span style="color: #0000FF;">>=</span><span style="color: #000000;">0.07</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">first</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">first</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">first</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">f</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">100</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1000</span><span style="color: #0000FF;">,</span><span style="color: #000000;">10000</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">then</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;">"Mean proportion of trailing zeroes in factorials to %d is %f\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ratio</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">e</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">elapsed</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">time</span><span style="color: #0000FF;">()-</span><span style="color: #000000;">t0</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;">"The mean proportion dips permanently below 0.07 at %d. (%s)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">first</span><span style="color: #0000FF;">,</span><span style="color: #000000;">e</span><span style="color: #0000FF;">})</span>
<!--</lang>-->
{{out}}
<pre>
Mean proportion of trailing zeroes in factorials to 100 is 0.170338
Mean proportion of trailing zeroes in factorials to 1000 is 0.116334
Mean proportion of trailing zeroes in factorials to 10000 is 0.081267
The mean proportion dips permanently below 0.07 at 31549. (0.1s)
</pre>
 
=={{header|Python}}==
Petelomax
7,805

edits

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