heap sort javascript
var array_length;
/* to create MAX array */
function heap_root(input, i) {
var left = 2 * i + 1;
var right = 2 * i + 2;
var max = i;
if (left < array_length && input[left] > input[max]) {
max = left;
}
if (right < array_length && input[right] > input[max]) {
max = right;
}
if (max != i) {
swap(input, i, max);
heap_root(input, max);
}
}
function swap(input, index_A, index_B) {
var temp = input[index_A];
input[index_A] = input[index_B];
input[index_B] = temp;
}
function heapSort(input) {
array_length = input.length;
for (var i = Math.floor(array_length / 2); i >= 0; i -= 1) {
heap_root(input, i);
}
for (i = input.length - 1; i > 0; i--) {
swap(input, 0, i);
array_length--;
heap_root(input, 0);
}
}
var arr = [3, 0, 2, 5, -1, 4, 1];
heapSort(arr);
console.log(arr);