Closest-pair problem: Difference between revisions

Line 4,193:

if high=='' | high=="," then high= 20000 /* " " " " " " */

if datatype(seed, 'W') then call random ,,seed /*seed for RANDOM (BIF) repeatability.*/

w=length(high); w=w + (w//2==0) /*W: for aligning the output columns.*/

w= length(high); w= w + (w//2==0) /*W: for aligning the output columns.*/

/*╔══════════════════════╗*/ do j=1 for N /*generate N random points*/

/*║ generate N points. ║*/ @x.j= random(low, high) /* " a random X */

/*╚══════════════════════╝*/ @y.j= random(low, high) /* " " " Y */

end /*j*/ /*X & Y make the point.*/

A=1; B=2 /* [↓] MINDD is actually the squared*/

A= 1; B= 2 /* [↓] MINDD is actually the squared*/

minDD= (@x.A - @x.B)**2 + (@y.A - @y.B)**2 /*distance between the first two points*/

/* [↓] use of XJ & YJ speed things up.*/

do j=1 for N-1; xj= @x.j; yj= @y.j /*find minimum distance between a ··· */

do k=j+1 to N /* ··· point and all the other points.*/

do k=j+1 for N-j-1 /* ··· point and all the other points.*/

dd= (xj - @x.k)**2 + (yj - @y.k)**2 /*compute squared distance from points.*/

if dd<minDD then parse value dd j k with minDD A B

Line 4,211:

say left('', length($) - 1) "["right(@x.A, w)',' right(@y.A, w)"]"

say left('', length($) - 1) "["right(@x.B, w)',' right(@y.B, w)"]"

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

exit 0 /*stick a fork in it, we're all done. */

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

sqrt: procedure; parse arg x; if x=0 then return 0; d=digits(); m.=9; numeric form; h=d+6