复杂排序---堆排序

function heapSort(array) {
    function swap(array, i, j) {
        var temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }

    function maxHeapify(array, index, heapSize) {
        var iMax,
            iLeft,
            iRight;
        while (true) {
            iMax = index;
            iLeft = 2 * index + 1;
            iRight = 2 * (index + 1);
            if (iLeft < heapSize && array[index] < array[iLeft]) {
                iMax = iLeft;
            }
            if (iRight < heapSize && array[iMax] < array[iRight]) {
                iMax = iRight;
            }
            if (iMax != index) {
                swap(array, iMax, index);
                index = iMax;
            } else {
                break;
            }
        }
    }

    function buildMaxHeap(array) {
        var i,
            iParent = Math.floor(array.length / 2) - 1;
        for (i = iParent; i >= 0; i--) {
            maxHeapify(array, i, array.length);
        }
    }

    function sort(array) {
        buildMaxHeap(array);
        for (var i = array.length - 1; i > 0; i--) {
            swap(array, 0, i);
            maxHeapify(array, 0, i);
        }
        return array;
    }

    return sort(array);
}