Sorting algorithms/Quicksort: Difference between revisions

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 =={{header|UnixPipes}}==
+ split() {
- # though it looks imperative at first sight, the logic is actually
+    (pivot=$1; lc=$2; gc=$3;
- # a pipeline split again and again into smaller ones and joined together.
+    while read n ; do
+        test $pivot -gt $n && echo $n > $lc || echo $n > $gc
+    done)
+ }
  qsort() {
-    lc="1.$1" ; gc="2.$1"
+   lc="1.$1" ; gc="2.$1"
-    read pivot; while read n ; do
+   read pivot; test -n "$pivot" && (
-        test $pivot -gt $n && echo $n >> $lc || echo $n >> $gc
+       split $pivot >(cat >> $lc) >( cat >> $gc);
+       (cat -s $lc | qsort $lc ) echo $pivot; (cat -s $gc | qsort $gc )
-    done
+   )
-    test -n "$pivot" && ( (cat -s $lc | qsort $lc ); echo $pivot; (cat -s $gc | qsort $gc ))
-    rm -f $lc $gc;
+   rm -f $lc $gc;
  }
  cat to.sort | qsort