Permutations/Derangements: Difference between revisions

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=={{header|Phix}}==
=={{header|Phix}}==
{{libheader|Phix/mpfr}}
{{libheader|Phix/mpfr}}
<lang Phix>function deranged(sequence s1, sequence s2)
<!--<lang Phix>(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
for i=1 to length(s1) do
<span style="color: #008080;">function</span> <span style="color: #000000;">deranged</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">s1</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">s2</span><span style="color: #0000FF;">)</span>
if s1[i]==s2[i] then return 0 end if
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s1</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
end for
<span style="color: #008080;">if</span> <span style="color: #000000;">s1</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]==</span><span style="color: #000000;">s2</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
return 1
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">1</span>

<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function derangements(integer n)
sequence ts = tagset(n)
<span style="color: #008080;">function</span> <span style="color: #000000;">derangements</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
sequence res = {}
<span style="color: #004080;">sequence</span> <span style="color: #000000;">ts</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
for i=1 to factorial(n) do
<span style="color: #004080;">sequence</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
sequence s = permute(i,ts)
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">factorial</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
if deranged(s,ts) then
<span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">permute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">i</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ts</span><span style="color: #0000FF;">)</span>
res = append(res,s)
<span style="color: #008080;">if</span> <span style="color: #000000;">deranged</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ts</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
end if
<span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">,</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
end for
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
return res
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">res</span>

<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function subfactorial(integer n)
if n<2 then return 1-n end if
<span style="color: #008080;">function</span> <span style="color: #000000;">subfactorial</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
return (n-1)*(subfactorial(n-1)+subfactorial(n-2))
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;"><</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">n</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end function
<span style="color: #008080;">return</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><span style="color: #000000;">subfactorial</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><span style="color: #000000;">subfactorial</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">-</span><span style="color: #000000;">2</span><span style="color: #0000FF;">))</span>

<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
?derangements(4)
for n=0 to 9 do
<span style="color: #0000FF;">?</span><span style="color: #000000;">derangements</span><span style="color: #0000FF;">(</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)</span>
printf(1,"%d: counted:%d, calculated:%d\n",{n,length(derangements(n)),subfactorial(n)})
<span style="color: #008080;">for</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">to</span> <span style="color: #000000;">9</span> <span style="color: #008080;">do</span>
end for
<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;">"%d: counted:%d, calculated:%d\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">derangements</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)),</span><span style="color: #000000;">subfactorial</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)})</span>
string msg = iff(machine_bits()=32?" (incorrect on 32-bit!)":"") -- (fine on 64-bit)
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
printf(1,"!20=%d%s\n",{subfactorial(20),msg})
<span style="color: #004080;">string</span> <span style="color: #000000;">msg</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">machine_bits</span><span style="color: #0000FF;">()=</span><span style="color: #000000;">32</span><span style="color: #0000FF;">?</span><span style="color: #008000;">" (incorrect on 32-bit!)"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">""</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- (fine on 64-bit)</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;">"!20=%d%s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">subfactorial</span><span style="color: #0000FF;">(</span><span style="color: #000000;">20</span><span style="color: #0000FF;">),</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">})</span>
include mpfr.e
function mpz_sub_factorial(integer n)
<span style="color: #008080;">include</span> <span style="color: #004080;">mpfr</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
-- probably not the most efficient way to do this!
<span style="color: #008080;">function</span> <span style="color: #000000;">mpz_sub_factorial</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
if n<2 then return sprintf("%d",{1-n}) end if
<span style="color: #000080;font-style:italic;">-- probably not the most efficient way to do this!</span>
mpz f = mpz_init(mpz_sub_factorial(n-1)),
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;"><</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%d"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">n</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
g = mpz_init(mpz_sub_factorial(n-2))
<span style="color: #004080;">mpz</span> <span style="color: #000000;">f</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">mpz_init</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mpz_sub_factorial</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>
mpz_add(f,f,g)
<span style="color: #000000;">g</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">mpz_init</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mpz_sub_factorial</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">-</span><span style="color: #000000;">2</span><span style="color: #0000FF;">))</span>
mpz_mul_si(f,f,n-1)
<span style="color: #7060A8;">mpz_add</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,</span><span style="color: #000000;">g</span><span style="color: #0000FF;">)</span>
string res = mpz_get_str(f)
<span style="color: #7060A8;">mpz_mul_si</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,</span><span style="color: #000000;">f</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>
{f,g} = mpz_free({f,g})
<span style="color: #004080;">string</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">mpz_get_str</span><span style="color: #0000FF;">(</span><span style="color: #000000;">f</span><span style="color: #0000FF;">)</span>
return res
<span style="color: #0000FF;">{</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,</span><span style="color: #000000;">g</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">mpz_free</span><span style="color: #0000FF;">({</span><span style="color: #000000;">f</span><span style="color: #0000FF;">,</span><span style="color: #000000;">g</span><span style="color: #0000FF;">})</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">res</span>
printf(1,"!20=%s (mpfr)\n",{mpz_sub_factorial(20)})</lang>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</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;">"!20=%s (mpfr)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">mpz_sub_factorial</span><span style="color: #0000FF;">(</span><span style="color: #000000;">20</span><span style="color: #0000FF;">)})</span>
<!--</lang>-->
{{out}}
{{out}}
<pre>
<pre>
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!20=895014631192902121 (mpfr)
!20=895014631192902121 (mpfr)
</pre>
</pre>
<small>(under pwa/p2js you get a trailing "000" instead of "186" for the incorrect result)</small>

{{trans|FreeBASIC}}
{{trans|FreeBASIC}}
A more efficient method of calculating subfactorials (0 should be handled separately, or obviously prepend a 1 and extract with idx+1).<br>
A more efficient method of calculating subfactorials (0 should be handled separately, or obviously prepend a 1 and extract with idx+1).<br>
Should you instead of string results want an array of mpz for further calculations, use the mpz_init_set() call as shown:
Should you instead of string results want an array of mpz for further calculations, use the mpz_init_set() call as shown:
<lang Phix>include mpfr.e
<!--<lang Phix>(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
<span style="color: #008080;">include</span> <span style="color: #004080;">mpfr</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
function subfactorial(integer n)
sequence res = repeat(0,n)
<span style="color: #008080;">function</span> <span style="color: #000000;">subfactorial</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
mpz num = mpz_init(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;">n</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">mpz</span> <span style="color: #000000;">num</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">mpz_init</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
for i=1 to n do
mpz_mul_si(num,num,i)
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
if mpz_odd(num) then
<span style="color: #7060A8;">mpz_mul_si</span><span style="color: #0000FF;">(</span><span style="color: #000000;">num</span><span style="color: #0000FF;">,</span><span style="color: #000000;">num</span><span style="color: #0000FF;">,</span><span style="color: #000000;">i</span><span style="color: #0000FF;">)</span>
mpz_sub_ui(num,num,1)
<span style="color: #008080;">if</span> <span style="color: #7060A8;">mpz_odd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">num</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
else
<span style="color: #7060A8;">mpz_sub_ui</span><span style="color: #0000FF;">(</span><span style="color: #000000;">num</span><span style="color: #0000FF;">,</span><span style="color: #000000;">num</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
mpz_add_ui(num,num,1)
<span style="color: #008080;">else</span>
end if
<span style="color: #7060A8;">mpz_add_ui</span><span style="color: #0000FF;">(</span><span style="color: #000000;">num</span><span style="color: #0000FF;">,</span><span style="color: #000000;">num</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
res[i] = mpz_get_str(num)
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
-- res[i] = mpz_init_set(num)
<span style="color: #000000;">res</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">mpz_get_str</span><span style="color: #0000FF;">(</span><span style="color: #000000;">num</span><span style="color: #0000FF;">)</span>
end for
<span style="color: #000080;font-style:italic;">-- res[i] = mpz_init_set(num)</span>
return res
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">res</span>

<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
?extract(subfactorial(20),tagset(9)&20)</lang>
<span style="color: #0000FF;">?</span><span style="color: #7060A8;">extract</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subfactorial</span><span style="color: #0000FF;">(</span><span style="color: #000000;">20</span><span style="color: #0000FF;">),</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">9</span><span style="color: #0000FF;">)&</span><span style="color: #000000;">20</span><span style="color: #0000FF;">)</span>
<!--</lang>-->
{{out}}
{{out}}
<pre>{"0","1","2","9","44","265","1854","14833","133496","895014631192902121"}</pre>
<pre>{"0","1","2","9","44","265","1854","14833","133496","895014631192902121"}</pre>