' FACTORS.BAS ----01/94---- QBasic --- hh ' First version written in 1979 for the Apple II computer ' Time Difference function added 1/94 DEFDBL A-E, G-Z DECLARE FUNCTION TimeDiff& (FirstTime\$, SecondTime\$) REM GOSUB 440 220 FOR F = 1 TO R E = N / F: IF INT(E) <> E THEN 310 IF E < F THEN 310 B = F: D = E F1 = F1 * -1 IF F1 = 1 THEN PRINT B, D, : ELSE PRINT B, D, "Pair No. "; FP - 1; "&"; FP T = T + B + D 290 IF T > 2000000000000000# THEN F2 = 1: T = 0 FP = FP + 1 310 NEXT F IF B = D THEN T = T - B EndTime\$ = TIME\$ PRINT "Elapsed time in seconds ="; TimeDiff&(StartTime\$, EndTime\$) PRINT "Sum of Aliquot divisers is: "; T IF B = D THEN PRINT N; " is a Square Number" IF D = N THEN PRINT N; " is a Prime Number" IF T = N THEN PRINT N; " is a Perfect Number" IF T < N THEN PRINT N; " is a Deficient Number" IF T > N THEN PRINT N; " is an Abundant Number" IF BELL = 1 THEN PRINT CHR\$(7) 420 PRINT : GOSUB 550: GOTO 220 430 PRINT TAB(25); "***************": RETURN 440 KEY OFF: CLS : LOCATE 3, 25: GOSUB 430: PRINT TAB(25); "FP FACTOR PAIRS": GOSUB 430 GOSUB 430 PRINT : PRINT "Some Definitions----a number is...." PRINT : PRINT "PRIME..... if the only factors are itself & one." PRINT "PERFECT... if equal to the sum of its factors." PRINT "SQUARE.... if equal to a factor squared." PRINT "DEFICIENT. if greater then the sum of its factors." PRINT "ABUNDANT.. if smaller then the sum of its factors." PRINT : INPUT "Do you want a signal on completion ? (Y/'Return') "; B\$ IF B\$ = "Y" OR B\$ = "y" THEN BELL = 1 550 PRINT : INPUT "What number do you wish factored ? (enter '0' to end) "; N IF N = 0 THEN GOTO 640 ELSE IF N = 1 GOTO 550 F1 = -1: FP = 1 T = -N R = INT(SQR(N)) + 1: PRINT IF R > 9999999! GOTO 650 PRINT : PRINT "The Factor Pairs of "; N; " are:" StartTime\$ = TIME\$ RETURN 640 CLS : KEY ON: END 650 PRINT N; " is too large for this program to factor." GOTO 420 REM The size of the numbers capable of being factored by this program REM is limited by the variable F which must be single precision. REM 9,999,998 squared is 99,999,960,000,004. (9,999,999^ is too big!) REM largest possible number (with ths program) is 99,999,971,016,703. REM try 32749,32760,32761,12960000,466560000,59999999999 (that's ten 9's) REM or 21,767,823,360,000 (4665600^, 558 factor pairs) REM but allow about 11 hours !!! (on a 8080 based machine) REM (about 1 hr on my 16 Mhz 386 -- 116 sec on 66 Mhz 486) REM Written by H.Heinz in Aug./79 for Apples B.C. users group. REM Adapted for Victor (with double precision) in June /83 REM Phone # (I'm interested in Rec. Math. Programs) 604-584-5501 FUNCTION TimeDiff& (FirstTime\$, SecondTime\$) HrDiff% = VAL(LEFT\$(SecondTime\$, 2)) - VAL(LEFT\$(FirstTime\$, 2)) MinDiff% = VAL(MID\$(SecondTime\$, 4, 2)) - VAL(MID\$(FirstTime\$, 4, 2)) SecDiff% = VAL(MID\$(SecondTime\$, 7, 2)) - VAL(MID\$(FirstTime\$, 7, 2)) TimeDiff& = 3600& * HrDiff% + 60 * MinDiff% + SecDiff% END FUNCTION