51 lines
1.8 KiB
Text
51 lines
1.8 KiB
Text
100H: /* FIND SOME PERFECT NUMBERS: NUMBERS EQUAL TO THE SUM OF THEIR PROPER */
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/* DIVISORS */
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/* CP/M SYSTEM CALL AND I/O ROUTINES */
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BDOS: PROCEDURE( FN, ARG ); /* CP/M BDOS SYSTEM CALL */
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DECLARE FN BYTE, ARG ADDRESS;
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GOTO 5;
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END BDOS;
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PR$CHAR: PROCEDURE( C ); DECLARE C BYTE; CALL BDOS( 2, C ); END;
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PR$STRING: PROCEDURE( S ); DECLARE S ADDRESS; CALL BDOS( 9, S ); END;
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PR$NL: PROCEDURE; CALL PR$CHAR( 0DH ); CALL PR$CHAR( 0AH ); END;
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PR$NUMBER: PROCEDURE( N );
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DECLARE N ADDRESS;
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DECLARE V ADDRESS, N$STR( 6 ) BYTE, W BYTE;
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V = N;
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W = LAST( N$STR );
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N$STR( W ) = '$';
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N$STR( W := W - 1 ) = '0' + ( V MOD 10 );
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DO WHILE( ( V := V / 10 ) > 0 );
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N$STR( W := W - 1 ) = '0' + ( V MOD 10 );
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END;
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CALL PR$STRING( .N$STR( W ) );
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END PR$NUMBER;
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/* TASK */
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/* RETURNS TRUE IF N IS PERFECT, 0 OTHERWISE */
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IS$PERFECT: PROCEDURE( N )BYTE;
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DECLARE N ADDRESS;
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DECLARE ( F1, F2, SUM ) ADDRESS;
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SUM = 1;
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F1 = 2;
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F2 = N;
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DO WHILE( F1 * F1 <= N );
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IF N MOD F1 = 0 THEN DO;
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SUM = SUM + F1;
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F2 = N / F1;
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/* AVOID COUNTING E.G., 2 TWICE AS A FACTOR OF 4 */
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IF F2 > F1 THEN SUM = SUM + F2;
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END;
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F1 = F1 + 1;
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END;
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RETURN SUM = N;
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END IS$PERFECT ;
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/* TEST IS$PERFECT */
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DECLARE N ADDRESS;
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DO N = 2 TO 10$000;
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IF IS$PERFECT( N ) THEN DO;
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CALL PR$CHAR( ' ' );
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CALL PR$NUMBER( N );
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END;
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END;
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EOF
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