Java优先级队列实现

优先级队列数组实现：

public class PriorityQueue {
	private int[] data;
	private int size;

	public PriorityQueue(int size){
		data = new int[size];
		this.size = 0;
	}

	public void push(int toInsert) throws Exception{
		if(size == data.length)
			throw new Exception("Queue is full!");
		if(size == 0){
			data[0] = toInsert;
		}else{
			int i = size -1;
			for( ; i >= 0 ; i--){
				if(data[i] < toInsert){
					data[i+1] = data[i];
				}else{
					break;
				}
			}
			data[i+1] = toInsert;
		}
		size++;
	}

	public int pop() throws Exception{
		if(this.size == 0)
			throw new Exception("Queue is empty!");
		return data[--size];
	}

	public int peek() throws Exception{
		if(this.size == 0)
			throw new Exception("Queue is empty!");
		return data[size-1];
	}

	public int size(){
		return this.size;
	}

	public boolean isEmpty(){
		return (size == 0);
	}

	public boolean isFull(){
		return (size == data.length);
	}
}

由于插入操作有可能需要移动数组中的数据项，故插入操作的时间复杂度为(0+N)/2，即O(N)

删除操作的时间复杂度为O(1)