September 2017 Update

Task/Sorting-algorithms-Heapsort/Zkl/sorting-algorithms-heapsort-1.zkl

@@ -0,0 +1,19 @@
+fcn heapSort(a){  // in place
+   n := a.len();
+   foreach start in ([(n-2)/2 .. 0,-1])
+      { siftDown(a, start, n-1) }
+   foreach end in ([n-1 .. 1,-1]){
+      a.swap(0, end);
+      siftDown(a, 0, end-1);
+   }
+   a
+}
+
+fcn siftDown(a, start, end){
+   while((child := start*2 + 1) <= end){
+      if(child < end and a[child]<a[child+1]) child+=1;
+      if(a[start] >= a[child]) return();
+      a.swap(start, child);
+      start = child;
+   }
+}

Task/Sorting-algorithms-Heapsort/Zkl/sorting-algorithms-heapsort-2.zkl

@@ -0,0 +1,2 @@
+heapSort(L(170, 45, 75, -90, -802, 24, 2, 66)).println();
+heapSort("this is a test".split("")).println();