aparler/RosettaCodeData
1
0
Fork 0
Code Issues 12 Pull requests 3 Projects Releases Packages Wiki Activity Actions

Initial data commit

Browse source
This commit is contained in:
Ingy döt Net 2023-07-01 11:58:00 -04:00
parent 72d218235f
commit f23f22d71c
199087 changed files with 3378941 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

56
Task/Dijkstras-algorithm/REXX/dijkstras-algorithm.rexx Normal file
View file

@ -0,0 +1,56 @@
/*REXX program determines the least costly path between two vertices given a list. */
$.= copies(9, digits() ) /*edge cost: indicates doesn't exist. */
xList= '!. @. $. beg fin bestP best$ xx yy' /*common EXPOSEd variables for subs. */
@abc= 'abcdefghijklmnopqrstuvwxyz' /*list of all the possible vertices. */
verts= 0; edges= 0 /*the number of vertices and also edges*/
do #=1 for length(@abc); _= substr(@abc, #, 1)
call value translate(_), #; @@.#= _
end /*#*/
call def$ a b 7 /*define an edge and its cost. */
call def$ a c 9 /* " " " " " " */
call def$ a f 14 /* " " " " " " */
call def$ b c 10 /* " " " " " " */
call def$ b d 15 /* " " " " " " */
call def$ c d 11 /* " " " " " " */
call def$ c f 2 /* " " " " " " */
call def$ d e 6 /* " " " " " " */
call def$ e f 9 /* " " " " " " */
beg= a; fin= e /*the BEGin and FINish vertexes. */
say; say 'number of edges = ' edges
say 'number of vertices = ' verts " ["left(@abc, verts)"]"
best$= $.; bestP=
say; do jv=2 to verts; call paths verts, jv; end /*jv*/
@costIs= right('cost =', 16)
if bestP==$. then say 'no path found.'
else say 'best path =' translate(bestP, @abc, 123456789) @costIs best$
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
apath: parse arg pathx 1 p1 2 p2 3; Lp= length(pathx); $= $.p1.p2
if $>=best$ then return
pv= p2; do ka=3 to Lp; _= substr(pathx, ka, 1)
if $.pv._>=best$ then return
$= $ + $.pv._; if $>=best$ then return; pv= _
end /*ka*/
best$= $; bestP= pathx
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
def$: parse arg xx yy $ .; if $.xx.yy<$ & $.yy.xx<$ | xx==yy then return
edges= edges + 1; verts= verts + ($.xx\==0) + ($.yy\==0)
$.xx= 0; $.yy= 0; $.xx.yy= $
say left('', 40) "cost of " @@.xx '───►' @@.yy " is " $
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
paths: procedure expose (xList); parse arg xx, yy, @.
do kp=1 for xx; _= kp; !.kp= _; end /*build a path list.*/
call .path 1
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
.path: procedure expose (xList); parse arg ?, _
if ?>yy then do; if @.1\==beg | @.yy\==fin then return
do #=1 for yy; _= _ || @.#; end /*#*/; call apath _
end
else do qq=1 for xx /*build vertex paths recursively*/
do kp=1 for ?-1; if @.kp==!.qq then iterate qq; end /*kp*/
@.?= !.qq; call .path ?+1 /*recursive call for next path. */
end /*qq*/
return