36、无界堆和跳表实现的优先队列

无界堆和跳表实现的优先队列

1. 无界堆基于的优先队列

1.1 顺序堆的 removeMin 方法

顺序堆的 removeMin 方法用于移除堆中优先级最小的元素。以下是该方法的代码：

public T removeMin() {
    int bottom = --next;
    T item = heap[ROOT].item;
    heap[ROOT] = heap[bottom];
    if (bottom == ROOT) {
        return item;
    }
    int child = 0;
    int parent = ROOT;
    while (parent < heap.length / 2) {
        int left = parent * 2; int right = (parent * 2) + 1;
        if (left >= next) {
            return item;
        } else if (right >= next || heap[left].score < heap[right].score) {
            child = left;
        } else {
            child = right;
        }
        if (heap[child].score < heap[parent].score) {
            swap