June 2018 Update

Task/Sorting-algorithms-Heapsort/Maple/sorting-algorithms-heapsort.maple

@@ -0,0 +1,36 @@
+swap := proc(arr, a, b)
+	local temp:
+	temp := arr[a]:
+	arr[a] := arr[b]:
+	arr[b] := temp:
+end proc:
+heapify := proc(toSort, n, i)
+	local largest, l, r, holder:
+	largest := i:
+	l := 2*i:
+	r := 2*i+1:
+	if (l <= n and toSort[l] > toSort[largest]) then
+		largest := l:
+	end if:
+	if (r <= n and toSort[r] > toSort[largest]) then
+		largest := r:
+	end if:
+	if (not largest = i) then
+		swap(toSort, i, largest);
+		heapify(toSort, n, largest):
+	end if:
+end proc:
+heapsort := proc(arr)
+	local n,i:
+	n := numelems(arr):
+	for i from trunc(n/2) to 1 by -1 do
+		heapify(arr, n, i):
+	end do:
+	for i from n to 2 by -1 do
+		swap(arr, 1, i):
+		heapify(arr, i-1, 1):
+	end do:
+end proc:
+arr := Array([17,3,72,0,36,2,3,8,40,0]);
+heapsort(arr);
+arr;