Primes: n*2^m+1: Difference between revisions
Added PL/M
(Primes: n*2^m+1 in FreeBASIC) |
(Added PL/M) |
||
Line 455:
399 2 1597
400 0 401
</pre>
=={{header|PL/M}}==
{{works with|8080 PL/M Compiler}} ... under CP/M (or an emulator)
Interestingly, the primes up to m = 45 all have a single digit m and will all fit in 16 bits, which is handy as the 8080 PL/M compiler doesn't support integers larger than unsigned 16-bit.
<syntaxhighlight lang="plm">
100H: /* FIND PRIMES OF THE FORM N * 2**M + 1 */
DECLARE FALSE LITERALLY '0';
DECLARE TRUE LITERALLY '0FFH';
/* CP/M SYSTEM CALL AND I/O ROUTINES */
BDOS: PROCEDURE( FN, ARG ); DECLARE FN BYTE, ARG ADDRESS; GOTO 5; END;
PR$CHAR: PROCEDURE( C ); DECLARE C BYTE; CALL BDOS( 2, C ); END;
PR$STRING: PROCEDURE( S ); DECLARE S ADDRESS; CALL BDOS( 9, S ); END;
PR$NL: PROCEDURE; CALL PR$CHAR( 0DH ); CALL PR$CHAR( 0AH ); END;
PR$NUMBER: PROCEDURE( N ); /* PRINTS A NUMBER IN THE MINIMUN FIELD WIDTH */
DECLARE N ADDRESS;
DECLARE V ADDRESS, N$STR ( 6 )BYTE, W BYTE;
V = N;
W = LAST( N$STR );
N$STR( W ) = '$';
N$STR( W := W - 1 ) = '0' + ( V MOD 10 );
DO WHILE( ( V := V / 10 ) > 0 );
N$STR( W := W - 1 ) = '0' + ( V MOD 10 );
END;
CALL PR$STRING( .N$STR( W ) );
END PR$NUMBER;
/* END SYSTEM CALL AND I/O ROUTINES */
/* SIEVE THE PRIMES TO 8000 */
DECLARE PRIME ( 8001 )BYTE;
DO;
DECLARE ( I, S ) ADDRESS;
PRIME( 0 ), PRIME( 1 ) = FALSE;
PRIME( 2 ) = TRUE;
DO I = 3 TO LAST( PRIME ) BY 2; PRIME( I ) = TRUE; END;
DO I = 4 TO LAST( PRIME ) BY 2; PRIME( I ) = FALSE; END;
DO I = 3 TO LAST( PRIME ) / 2 BY 2;
IF PRIME( I ) THEN DO;
DO S = I * I TO LAST( PRIME ) BY I + I; PRIME( S ) = FALSE; END;
END;
END;
END;
DECLARE MAX$M LITERALLY '30'; /* MAXIMUM M WE WILL CONSIDER */
/* FIND THE PRIMES */
DECLARE ( N, M, P, TWO$TO$M ) ADDRESS;
DECLARE NOT$FOUND BYTE;
DO N = 1 TO 45;
M = 0;
TWO$TO$M = 1;
P = 0;
NOT$FOUND = 1;
DO WHILE M <= MAX$M
AND ( NOT$FOUND := NOT PRIME( P := ( N * TWO$TO$M ) + 1 ) );
TWO$TO$M = TWO$TO$M + TWO$TO$M;
M = M + 1;
END;
CALL PR$CHAR( '(' );
IF N < 10 THEN CALL PR$CHAR( ' ' );
CALL PR$NUMBER( N );
IF NOT$FOUND THEN DO;
CALL PR$STRING( .' NOT FOUND$' );
END;
ELSE DO;
CALL PR$CHAR( ' ' );
CALL PR$NUMBER( M );
CALL PR$CHAR( ':' );
CALL PR$CHAR( ' ' );
IF P < 10 THEN CALL PR$CHAR( ' ' );
IF P < 100 THEN CALL PR$CHAR( ' ' );
IF P < 1000 THEN CALL PR$CHAR( ' ' );
CALL PR$NUMBER( P );
CALL PR$CHAR( ' ' );
CALL PR$CHAR( ' ' );
END;
CALL PR$CHAR( ')' );
IF N MOD 5 = 0 THEN CALL PR$NL;
END;
EOF
</syntaxhighlight>
{{out}}
<pre>
( 1 0: 2 )( 2 0: 3 )( 3 1: 7 )( 4 0: 5 )( 5 1: 11 )
( 6 0: 7 )( 7 2: 29 )( 8 1: 17 )( 9 1: 19 )(10 0: 11 )
(11 1: 23 )(12 0: 13 )(13 2: 53 )(14 1: 29 )(15 1: 31 )
(16 0: 17 )(17 3: 137 )(18 0: 19 )(19 6: 1217 )(20 1: 41 )
(21 1: 43 )(22 0: 23 )(23 1: 47 )(24 2: 97 )(25 2: 101 )
(26 1: 53 )(27 2: 109 )(28 0: 29 )(29 1: 59 )(30 0: 31 )
(31 8: 7937 )(32 3: 257 )(33 1: 67 )(34 2: 137 )(35 1: 71 )
(36 0: 37 )(37 2: 149 )(38 5: 1217 )(39 1: 79 )(40 0: 41 )
(41 1: 83 )(42 0: 43 )(43 2: 173 )(44 1: 89 )(45 2: 181 )
</pre>
| |||