WP 34S: Shanks' Square Form Factorization Programme - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: Not HP Calculators (/forum-7.html) +--- Forum: Not quite HP Calculators - but related (/forum-8.html) +--- Thread: WP 34S: Shanks' Square Form Factorization Programme (/thread-1386.html) WP 34S: Shanks' Square Form Factorization Programme - Gerald H - 05-23-2014 05:45 AM Shanks' square form factorization finds a factor for composite integer input N. If the continued fraction expansion is too short the programme stops with the message "Elliptic" displayed - in this case N can be multiplied by a small odd factor, eg 3, 5, 7.... & factorization again attempted. The command "FND" is an attempt to reproduce the HP 42S hidden commend "[FIND]". Improvements & bug reports welcome. 1 LBL 'SQF' 2 DBLOFF 3 GTO 07 4 LBL 04 5 CLα 6 α'Ell' 7 α'ipt' 8 α'ic' 9 RCL 08 10 VIEWα 11 RTN 12 LBL 01 13 RCL 08 14 RCL+ X 15 LBL 07 16 CLREGS 17 STO 08 18 ENTER 19 √ 20 IP 21 STO 04 22 STO 02 23 x^2 24 - 25 x=0? 26 GTO 00 27 STO 03 28 x=1? 29 GTO 01 30 # 010 31 STO 09 32 CF 00 33 # 008 34 RCL* 02 35 √ 36 IP 37 STO 05 38 LBL 03 39 RCL 05 40 RCL 03 41 ODD? 42 SKIP 002 43 # 002 44 / 45 x>? Y 46 GTO 06 47 STO→ 09 48 ISG 09 49 LBL 06 50 RCL 02 51 ENTER 52 RCL+ 04 53 RCL 03 54 MOD 55 - 56 STO 04 57 x^2 58 +/- 59 RCL+ 08 60 RCL/ 03 61 STO 03 62 ENTER 63 √ 64 FS?C 00 65 GTO 03 66 SF 00 67 FP 68 x≠0? 69 GTO 03 70 1 71 RCL L 72 x=? Y 73 GTO 04 74 STO 06 75 XEQ 'FND' 76 x=1? 77 GTO 03 78 RCL 06 79 RCL 02 80 RCL- 04 81 RCL X 82 RCL 06 83 MOD 84 - 85 RCL+ 04 86 LBL 02 87 RCL 08 88 RCL Y 89 x^2 90 - 91 RCL/ 06 92 STO 06 93 RCL 02 94 RCL+ Z 95 x<>Y 96 MOD 97 +/- 98 RCL+ 02 99 x≠? Y 100 GTO 02 101 RCL 06 102 ODD? 103 RTN 104 # 002 105 / 106 RTN 107 LBL 00 108 RCL 04 109 RTN 110 LBL 'FND' 111 1 112 0 113 . 114 3 115 0 116 0 117 1 118 XEQ 'MFD' 119 # 040 120 x>? Y 121 SKIP 002 122 # 000 123 RTN 124 # 001 125 END