Balanced ternary: Difference between revisions

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exit /*stick a fork in it, we're all done. */

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d2bt: procedure; parse arg x 1; p=0; $.='-'; $.1='+'; $.0=0; #=

d2bt: procedure; parse arg x 1; p= 0; $.= '-'; $.1= "+"; $.0= 0; #=

x=x / 1

do until x==0; _= (x // (3** (p+1) ) ) % 3**p

if _== 2 then _= -~~1; else if _== -2 then _=~~1

if _== 2 then _= -1

~~x=x~~ - _ * ~~(3**p);~~ p=~~p+1;~~ #=~~$._~~ ~~|| #~~

else if _== -2 then _= 1

~~end~~ /*~~until~~*/; ~~return~~ #

x=x - _ * (3**p); p= p+1; #= $._ || #

end /*until*/; return #

/*──────────────────────────────────────────────────────────────────────────────────────*/

bt2d: procedure; parse arg x; r=reverse(x); #=0; $.=-1; $.0=0; _='+'; $._=1

bt2d: procedure; parse arg x; r= reverse(x); #= 0; $.= -1; $.0= 0; _= '+'; $._= 1

do j=1 for length(x); _=substr(r,j,1); #= # + $._ * 3**(j-1); end; return #

do j=1 for length(x); _= substr(r,j,1); #= # + $._ * 3**(j-1); end; return #

/*──────────────────────────────────────────────────────────────────────────────────────*/

btAdd: procedure; parse arg x,y; rx=reverse(x); ry=reverse(y); carry=0

btAdd: procedure; parse arg x,y; rx= reverse(x); ry= reverse(y); carry= 0

@.=0 ; _='-'; @._= -1; _="+"; @._=1

@.=0 ; _= '-'; @._= -1; _= "+"; @._= 1

$.='-'; $.0=0; $.1= '+'

$.= '-'; $.0= 0; $.1= '+'

#=; do j=1 for max( length(x), length(y) )

x_=substr(rx, j, 1); xn=@.x_

x_= substr(rx, j, 1); xn= @.x_

y_=substr(ry, j, 1); yn=@.y_

y_= substr(ry, j, 1); yn= @.y_

s=xn + yn + carry; carry= 0

s= xn + yn + carry; carry= 0

if s== 2 then do; s=-1; carry= 1; end

if s== 3 then do; s= 0; carry= 1; end

if s==-2 then do; s= 1; carry=-1; end

#=$.s || #

#= $.s || #

end /*j*/

if carry\==0 then #=$.carry || #; return btNorm(#)

if carry\==0 then #= $.carry || #; return btNorm(#)

/*──────────────────────────────────────────────────────────────────────────────────────*/

btMul: procedure; parse arg x 1 x1 2, y 1 y1 2; if x==0 | y==0 then return 0

S=1; x=btNorm(x); y=btNorm(y) /*handle: 0-xxx values.*/

S= 1; x= btNorm(x); y= btNorm(y) /*handle: 0-xxx values.*/

if x1=='-' then do; x=btNeg(x); S=-S; end /*positate the number. */

if x1=='-' then do; x= btNeg(x); S=-S; end /*positate the number. */

if y1=='-' then do; y=btNeg(y); S=-S; end /* " " " */

if y1=='-' then do; y= btNeg(y); S=-S; end /* " " " */

if length(y)>length(x) then parse value x y with y x /*optimize " " */

P=0

do until y==0 /*keep adding 'til done*/

P=btAdd(P, x) /*multiple the hard way*/

P= btAdd(P, x) /*multiple the hard way*/

y=btSub(y, '+') /*subtract 1 from Y.*/

y= btSub(y, '+') /*subtract 1 from Y.*/

end /*until*/

if S==-1 then P=btNeg(P); return P /*adjust the product sign; return. */

/*──────────────────────────────────────────────────────────────────────────────────────*/

btNeg: return translate(arg(1), '-+', "+-") /*negate bal_ternary #.*/

btNorm: _=strip(arg(1),'L',0); if _=='' then _=0; return _ /*normalize the number.*/

btNorm: _= strip(arg(1), 'L', 0); if _=='' then _=0; return _ /*normalize the number.*/

btSub: return btAdd(arg(1), btNeg(arg(2))) /*subtract two BT args.*/

btSub: return btAdd( arg(1), btNeg( arg(2) ) ) /*subtract two BT args.*/

btShow: say center(arg(1),9) right(arg(2),20) @@ right(bt2d(arg(2)),9) @; return</lang>

btShow: say center( arg(1), 9) right( arg(2), 20) @@ right( bt2d(arg(2)), 9) @; return</lang>

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