# TITLE:  Factoring by Fermat's Method 
# AUTHOR: Roy F.A. Maclean 
# EMAIL:  rfamgm at gmail
# WEB:    http://www.spiderpixel.co.uk/caspro        
# DATE:   15Jan1998       
# MAKE:   CASIO
# MODEL:  fx6300G or greater
# SIZE:   179       
# NOTES:  Enter a positive integer. If it is composite it will be 
#         broken into 2 factors.


@@ Program 1

Lbl 0
?->A:Goto 2
Lbl 1
2_
A/2->A:A=1=>Goto 0
Lbl 2
Frac .5A=0=>Goto 1
A=1=>Goto 0
Int sqrt(A)->S
Frac sqrt(A)<>0=>1+S->S
2S+1->U:1->V:S^2-A->R
R=0=>Goto 6
Lbl 4
R<0=>Goto 3
Lbl 5
R-V->R
V+2->V
R>0=>Goto 5
Lbl 3
R>=0=>Goto 7
R+U->R
U+2->U
Lbl 7
R<>0=>Goto 4
Lbl 6
(U+V-2)/2_
(U-V)/2->B
B<>1=>B_
Goto 0