Weird numbers: Difference between revisions
Added Algol 68
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70 836 4030 5830 7192 7912 9272 10430 10570 10792 10990 11410 11690 12110 12530 12670 13370 13510 13790 13930 14770 15610 15890 16030 16310
</pre>
=={{header|ALGOL 68}}==
{{Trans|Go}}
Translation of the untweaked Go version 1 sample. Avoids creating separate array slices in the semiperfect routine, to save memory for Algol 68G version 2.8.3.
<lang algol68>BEGIN # find wierd numbers - abundant but not semiperfect numbers - translation of Go #
# returns the divisors of n in descending order #
PROC divisors = ( INT n )[]INT:
BEGIN
INT max divs = 2 * ENTIER sqrt( n );
[ 1 : max divs ]INT divs;
[ 1 : max divs ]INT divs2;
INT d pos := 0, d2 pos := 0;
divs[ d pos +:= 1 ] := 1;
FOR i FROM 2 WHILE i * i <= n DO
IF n MOD i = 0 THEN
INT j = n OVER i;
divs[ d pos +:= 1 ] := i;
IF i /= j THEN divs2[ d2 pos +:= 1 ] := j FI
FI
OD;
FOR i FROM d pos BY -1 WHILE i > 0 DO
divs2[ d2 pos +:= 1 ] := divs[ i ]
OD;
divs2[ 1 : d2 pos ]
END # divisors # ;
# returns TRUE if n with divisors divs, is abundant, FALSE otherwise #
PROC abundant = ( INT n, []INT divs )BOOL:
BEGIN
INT sum := 0;
FOR i FROM LWB divs TO UPB divs DO sum +:= divs[ i ] OD;
sum > n
END # abundant # ;
# returns TRUE if n with divisors divs, is semiperfect, FALSE otherwise #
PROC semiperfect = ( INT n, []INT divs, INT lb, ub )BOOL:
IF ( ub - lb ) <= -1
THEN FALSE
ELIF INT h = divs[ lb ];
n < h
THEN semiperfect( n, divs, lb + 1, ub )
ELIF n = h
THEN TRUE
ELIF semiperfect( n - h, divs, lb + 1, ub )
THEN TRUE
ELSE semiperfect( n, divs, lb + 1, ub )
FI # semiperfect # ;
# returns a sieve where FALSE = abundant and not semiperfect #
PROC sieve = ( INT limit )[]BOOL:
BEGIN # Only interested in even numbers >= 2 #
[ 1 : limit ]BOOL w; FOR i FROM 1 TO limit DO w[ i ] := FALSE OD;
FOR i FROM 2 BY 2 TO limit DO
IF NOT w[ i ] THEN
[]INT divs = divisors( i );
IF NOT abundant( i, divs ) THEN
w[ i ] := TRUE
ELIF semiperfect( i, divs, LWB divs, UPB divs ) THEN
FOR j FROM i BY i TO limit DO w[ j ] := TRUE OD
FI
FI
OD;
w
END # sieve # ;
BEGIN # task #
[]BOOL w = sieve( 17 000 );
INT count := 0;
INT max = 25;
print( ( "The first 25 weird numbers are:", newline ) );
FOR n FROM 2 BY 2 WHILE count < max DO
IF NOT w[ n ] THEN
print( ( whole( n, 0 ), " " ) );
count +:= 1
FI
OD;
print( ( newline ) )
END
END</lang>
{{out}}
<pre>
The first 25 weird numbers are:
70 836 4030 5830 7192 7912 9272 10430 10570 10792 10990 11410 11690 12110 12530 12670 13370 13510 13790 13930 14770 15610 15890 16030 16310</pre>
=={{header|AppleScript}}==
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