Erdős-primes: Difference between revisions

{{works with|TinyBasic}}

(Tom Pittman's) TinyBasic uses <code>;</code> instead of <code>,</code> for string concatenation in <code>PRINT</code>.

<syntaxhighlight lang="basic">10 REM Erdős-primes

20 LET P = 1

30 IF P > 2 THEN LET P = P + 2

40 IF P < 3 THEN LET P = P + 1

50 LET Z = P

60 GOSUB 1000

70 IF A = 0 THEN GOTO 30

80 LET K = 0

90 LET K = K + 1

100 GOSUB 2000

110 LET Z = P - F

120 IF Z < 0 THEN GOTO 170

130 GOSUB 1000

140 IF A = 1 THEN LET E = 0

150 IF A = 1 THEN GOTO 30

160 GOTO 90

170 LET C = C + 1

180 IF P < 2500 THEN PRINT C, " ", P

190 IF P > 2500 THEN END

200 GOTO 30

990 REM primality of Z by trial division, result is in A

1000 LET Y = 1

1010 LET A = 0

1020 IF Z = 2 THEN LET A = 1

1030 IF Z < 3 THEN RETURN

1040 LET Y = Y + 2

1050 IF (Z / Y) * Y = Z THEN RETURN

1060 IF Y * Y < Z THEN GOTO 1040

1070 LET A = 1

1080 RETURN

1990 REM factorial of K, result is in F

2000 LET A = 1

2010 LET F = 1

2020 LET F = F * A

2030 IF A = K THEN RETURN

2040 LET A = A + 1

2050 GOTO 2020

3000 REM TODO: Simplify. K! can be calculated from (K - 1)!.</syntaxhighlight>