September 2017 Update

Task/Sorting-algorithms-Heapsort/JavaScript/sorting-algorithms-heapsort.js

@@ -0,0 +1,45 @@
+function swap(data, i, j) {
+    var tmp = data[i];
+    data[i] = data[j];
+    data[j] = tmp;
+}
+
+ function heap_sort(arr) {
+    put_array_in_heap_order(arr);
+    end = arr.length - 1;
+    while(end > 0) {
+        swap(arr, 0, end);
+        sift_element_down_heap(arr, 0, end);
+        end -= 1
+    }
+}
+
+function put_array_in_heap_order(arr) {
+    var i;
+    i = arr.length / 2 - 1;
+    i = Math.floor(i);
+    while (i >= 0) {
+        sift_element_down_heap(arr, i, arr.length);
+        i -= 1;
+    }
+}
+
+function sift_element_down_heap(heap, i, max) {
+    var i_big, c1, c2;
+    while(i < max) {
+        i_big = i;
+        c1 = 2*i + 1;
+        c2 = c1 + 1;
+        if (c1 < max && heap[c1] > heap[i_big])
+            i_big = c1;
+        if (c2 < max && heap[c2] > heap[i_big])
+            i_big = c2;
+        if (i_big == i) return;
+        swap(heap,i, i_big);
+        i = i_big;
+    }
+}
+
+arr = [12, 11, 15, 10, 9, 1, 2, 3, 13, 14, 4, 5, 6, 7, 8,];
+heap_sort(arr);
+alert(arr);