1 files changed, 35 insertions, 37 deletions

diff --git a/test/sort.lua b/test/sort.lua
index 14d4cf22..d665e96b 100644
--- a/test/sort.lua
+++ b/test/sort.lua
@@ -1,28 +1,25 @@
 $debug
 
-function quicksort(r,s)
-	if s<=r then return end		-- caso basico da recursao
-	local v, i, j = x[r], r, s+1
-		i=i+1; while x[i]<v do i=i+1 end
-		j=j-1; while x[j]>v do j=j-1 end
-		x[i],x[j]=x[j],x[i]
-	while j>i do			-- separacao
-		i=i+1; while x[i]<v do i=i+1 end
-		j=j-1; while x[j]>v do j=j-1 end
-		x[i],x[j]=x[j],x[i]
-	end
-	x[i],x[j]=x[j],x[i]		-- undo last swap
-	x[j],x[r]=x[r],x[j]
-	quicksort(r,j-1)		-- recursao
-	quicksort(j+1,s)
+function quicksort(a,r,s)
+ if s<=r then return end
+ local v, i, j = a[r], r, s+1
+ repeat
+  i=i+1; while a[i]<v do i=i+1 end
+  j=j-1; while a[j]>v do j=j-1 end
+  a[i],a[j]=a[j],a[i]
+ until j<=i
+ a[i],a[j]=a[j],a[i]			-- undo last swap
+ a[j],a[r]=a[r],a[j]
+ quicksort(a,r,j-1)
+ quicksort(a,j+1,s)
 end
 
-function sort(a,n)			-- selection sort
+function selectionsort(a,n)
  local i=1
  while i<=n do
   local m, j = i, i+1
   while j<=n do
-   if a[j]<a[m] then m=j end
+   if a[j]>a[m] then m=j end		-- reverse sort
    j=j+1
   end
  a[i],a[m]=a[m],a[i]			-- swap a[i] and a[m]
@@ -30,25 +27,26 @@ function sort(a,n)			-- selection sort
  end
 end
 
-function main()
- x={}
- n=-1
- n=n+1;	x[n]="a"
- n=n+1;	x[n]="waldemar"
- n=n+1;	x[n]="luiz"
- n=n+1;	x[n]="lula"
- n=n+1;	x[n]="peter"
- n=n+1;	x[n]="raquel"
- n=n+1;	x[n]="camilo"
- n=n+1;	x[n]="andre"
- n=n+1;	x[n]="marcelo"
- n=n+1;	x[n]="sedrez"
- n=n+1;	x[n]="z"
- print(x[0]..","..x[1]..","..x[2]..","..x[3]..","..x[4]..","..x[5]..","..x[6]..","..x[7]..","..x[8]..","..x[9]..","..x[10])
- quicksort(1,n-1)
- print(x[0]..","..x[1]..","..x[2]..","..x[3]..","..x[4]..","..x[5]..","..x[6]..","..x[7]..","..x[8]..","..x[9]..","..x[10])
- sort (x, n-1)
- print(x[0]..","..x[1]..","..x[2]..","..x[3]..","..x[4]..","..x[5]..","..x[6]..","..x[7]..","..x[8]..","..x[9]..","..x[10])
+function show(m,x)
+ write(m.."\n\t")
+ local i=0
+ while x[i] do
+  write(x[i])
+  i=i+1
+  if x[i] then write(",") end
+ end
+ write("\n")
 end
 
-main()
+x={"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"}
+
+n=1	while x[n] do n=n+1 end		-- count elements
+x[0]="A"	x[n]="Z"		-- quicksort need sentinels
+
+show("original",x)
+
+quicksort(x,1,n-1)
+show("after quicksort",x)
+
+selectionsort(x, n-1)
+show("after reverse selection sort",x)