June 2018 Update

Task/Sorting-algorithms-Heapsort/Ring/sorting-algorithms-heapsort.ring

@@ -0,0 +1,53 @@
+# Project : Sorting algorithms/Heapsort
+# Date    : 2018/03/04
+# Author : Gal Zsolt [~ CalmoSoft ~]
+# Email   : <calmosoft@gmail.com>
+
+test = [4, 65, 2, -31, 0, 99, 2, 83, 782, 1]
+see "before sort:" + nl
+showarray(test)
+heapsort(test)
+see "after sort:" + nl
+showarray(test)
+
+func heapsort(a)
+cheapify(a)
+for e = len(a) to 1 step -1
+     temp = a[e]
+     a[e] = a[1]
+     a[1] = temp
+     siftdown(a, 1, e-1)
+next
+
+func cheapify(a)
+m = len(a)
+for s = floor((m - 1) / 2) to 1 step -1
+     siftdown(a,s,m)
+next
+
+func siftdown(a,s,e)
+r = s
+while r * 2 + 1 <= e
+         c = r * 2
+         if c + 1 <= e
+            if a[c] < a[c + 1]
+               c = c + 1
+            ok
+         ok
+         if a[r] < a[c]
+            temp = a[r]
+            a[r] = a[c]
+            a[c] = temp
+            r = c
+         else
+            exit
+         ok
+end
+
+func showarray(vect)
+        svect = ""
+        for n = 1 to len(vect)
+              svect = svect + vect[n] + " "
+        next
+        svect = left(svect, len(svect) - 1)
+        see svect + nl