堆排序golang实现

func heapSort(arr []int) {
    length := len(arr)
    // 构建初始堆
    for i := (length - 2) / 2; i >= 0; i-- {
        heapify(arr, i, length)
    }
    // 逐个取出堆顶元素
    for i := length - 1; i > 0; i-- {
        arr[0], arr[i] = arr[i], arr[0]
        heapify(arr, 0, i)
    }
}

func heapify(arr []int, index, length int) {
    left := 2*index + 1
    right := 2*index + 2
    maxIndex := index

    if left < length && arr[left] > arr[maxIndex] {
        maxIndex = left
    }

    if right < length && arr[right] > arr[maxIndex] {
        maxIndex = right
    }

    if maxIndex != index {
        arr[index], arr[maxIndex] = arr[maxIndex], arr[index]
        heapify(arr, maxIndex, length)
    }
}

func main() {
    arr := []int{5, 6, 7, 8, 1, 2, 3, 4, 0}
    fmt.Println(arr)
    heapSort(arr)
    fmt.Println(arr)
}

[5 6 7 8 1 2 3 4 0]
[0 1 2 3 4 5 6 7 8]