//heap sort test

function hpSort(){

length = data.length - 1;

while (length > 0) {

mkHeap(0);

swap(0, length);

length--;

}

}

function mkHeap(i) {

var node1 = i * 2 + 1;

var node2 = i * 2 + 2;

if (node1 > length) {

return

}

if (node1 == length) {

if (data[node1] > data[i]) {

swap(i, node1);

}

return

}

mkHeap (node1);

mkHeap (node2);

if (data[node1] >= data[node2]) {

largeNode = node1;

} else {

largeNode = node2;

}

if (data[i] < data[largeNode]) {

swap (i, largeNode);

mkHeap (largeNode);

}

}

function swap(a, b){

var num = data[a];

data[a] = data[b];

data[b] = num;

}

data = new Array();

data =[2,5,8,4,21,15,16,11,10,6,9,7,17,1];

hpSort();

alert (data);