(11C) Greatest Common Divisor
12-31-2017, 05:14 AM (This post was last modified: 12-31-2017 07:04 AM by Gamo.)
Post: #1
 Gamo Senior Member Posts: 471 Joined: Dec 2016
(11C) Greatest Common Divisor
Quick and Simple program to find GCD of two integers.

Code:
 01  LBL A 02  - 03  LSTx 04  X<>Y 05  ABS 06  X≠Y  ( for 15C [g TEST 6] ) 07  GTO A 08  R/S

Example: GCD (256, 656) is 16 --> 256 ENTER 656 A

GCD (9119, 1991) is 11 --> 9119 ENTER 1991 A

Gamo
01-08-2018, 01:29 AM
Post: #2
 Gamo Senior Member Posts: 471 Joined: Dec 2016
RE: (11C) Greatest Common Divisor
Another great version from member name Csaba Tizedes mention:

There is a 15C version as per Marcus du Sautoy explanation (in TV show 'Secrets Of Modern Living: Algorithms')

Also work for HP-11C

Code:
 LBL E x=y     / there are the two numbers are equal? RTN     / yes, stop here and the GCD on the display x>y     / no, check there are the smaller number in x? x<>y   / no, chsnge x and y   -       / let's substract it LSTx   / and get back the number of x GTO E / and again until numbers are equal