Composite numbers k with no single digit factors whose factors are all substrings of k: Difference between revisions
Composite numbers k with no single digit factors whose factors are all substrings of k (view source)
Revision as of 23:38, 23 February 2024
, 2 months agoAdded FreeBASIC
(Added Easylang) |
(Added FreeBASIC) |
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Line 342:
=={{header|EasyLang}}==
{{trans|C}} (optimized)
<syntaxhighlight>
fastfunc
while n > 0
if
if
.
else
if
n =
.
.
if
return 1
.
Line 366:
return 0
.
fastfunc test n .
if n mod 2 = 0 or n mod 3 = 0 or n mod 5 = 0 or n mod 7 = 0
return 0
.
if rest mod fact = 0
.
if
return 0
.
.
fact += 2
if fact > sqrt n and nfacts = 0
return 0
.
.
if
return 1
.
Line 391 ⟶ 394:
.
n = 11
while
if
print n
.
n += 2
.
</syntaxhighlight>
=={{header|F_Sharp|F#}}==
Line 435 ⟶ 436:
Real: 00:00:26.059
</pre>
=={{header|FreeBASIC}}==
{{trans|ALGOL 68}}
<syntaxhighlight lang="vbnet">Function isSubstring(kStr As String, f As Integer) As Integer
Dim As String fStr = Str(f)
Dim As Integer fLen = Len(fStr)
Dim As Integer result = 0
Dim As Integer fEnd = Len(kStr) - fLen + 1
For fPos As Integer = 1 To Len(kStr) - fLen + 1
If Mid(kStr, fPos, fLen) = fStr Then
result = -1
Exit For
End If
Next fPos
Return result
End Function
Dim As Integer requiredNumbers = 20
Dim As Integer kCount = 0
For k As Integer = 11 To 99999999 Step 2
If k Mod 3 <> 0 And k Mod 5 <> 0 And k Mod 7 <> 0 Then
Dim As Integer isCandidate = -1
Dim As String kStr = Str(k)
Dim As Integer v = k
Dim As Integer fCount = 0
For f As Integer = 11 To Sqr(k) + 1
If v Mod f = 0 Then
isCandidate = isSubstring(kStr, f)
If isCandidate Then
While v Mod f = 0
fCount += 1
v \= f
Wend
Else
Exit For
End If
End If
Next f
If isCandidate And (fCount > 1 Or (v <> k And v > 1)) Then
If v > 1 Then isCandidate = isSubstring(kStr, v)
If isCandidate Then
Print Using "#######,###"; k;
kCount += 1
If kCount Mod 10 = 0 Then Print
End If
End If
End If
If kCount >= requiredNumbers Then Exit For
Next k</syntaxhighlight>
{{out}}
<pre> 15,317 59,177 83,731 119,911 183,347 192,413 1,819,231 2,111,317 2,237,411 3,129,361
5,526,173 11,610,313 13,436,683 13,731,373 13,737,841 13,831,103 15,813,251 17,692,313 19,173,071 28,118,827</pre>
=={{header|Go}}==
Line 689 ⟶ 742:
19: 19_173_071
20: 28_118_827
</pre>
=={{header|PARI/GP}}==
<syntaxhighlight lang="PARI/GP">
/* Returns a substring of str starting at s with length n */
ssubstr(str, s = 1, n = 0) = {
my(vt = Vecsmall(str), ve, vr, vtn = #str, n1);
if (vtn == 0, return(""));
if (s < 1 || s > vtn, return(str));
n1 = vtn - s + 1; if (n == 0, n = n1); if (n > n1, n = n1);
ve = vector(n, z, z - 1 + s); vr = vecextract(vt, ve); return(Strchr(vr));
}
/* Checks if subStr is a substring of mainStr */
isSubstring(mainStr, subStr) = {
mainLen = #Vecsmall(mainStr);
subLen = #Vecsmall(subStr);
for (startPos = 1, mainLen - subLen + 1,
if (ssubstr(mainStr, startPos, subLen) == subStr,
return(1); /* True: subStr found in mainStr */
)
);
return(0); /* False: subStr not found */
}
/* Determines if a number's factors, all > 9, are substrings of its decimal representation */
contains_its_prime_factors_all_over_9(n) = {
if (n < 10 || isprime(n), return(0)); /* Skip if n < 10 or n is prime */
strn = Str(n); /* Convert n to string */
pfacs = factor(n)[, 1]; /* Get unique prime factors of n */
for (i = 1, #pfacs,
if (pfacs[i] <= 9, return(0)); /* Skip factors ≤ 9 */
if (!isSubstring(strn, Str(pfacs[i])), return(0)); /* Check if factor is a substring */
);
return(1); /* All checks passed */
}
/* Main loop to find and print numbers meeting the criteria */
{
found = 0; /* Counter for numbers found */
for (n = 0, 30 * 10^6, /* Iterate from 0 to 30 million */
if (contains_its_prime_factors_all_over_9(n),
found += 1; /* Increment counter if n meets criteria */
print1(n, " "); /* Print n followed by a space */
if (found % 10 == 0, print("")); /* Newline every 10 numbers */
if (found == 20, break); /* Stop after finding 20 numbers */
);
);
}
</syntaxhighlight>
{{out}}
<pre>
15317 59177 83731 119911 183347 192413 1819231 2111317 2237411 3129361
5526173 11610313 13436683 13731373 13737841 13831103 15813251 17692313 19173071 28118827
</pre>
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