golang的优先队列实现

先放一个入门版

package main

import (
	"container/heap"
	"fmt"
)

type Elem struct {
	Value    int // 数据
	Priority int // 优先级
	Index    int // 位置
}

type PriorityQueue []*Elem

func (pq PriorityQueue) Len() int {
	return len(pq)
}

func (pq PriorityQueue) Less(i int, j int) bool {
	return pq[i].Priority < pq[j].Priority
}

func (pq PriorityQueue) Swap(i int, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].Index, pq[j].Index = pq[j].Index, pq[i].Index
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	lenOfOld := len(old)
	item := old[ lenOfOld-1 ]
	*pq = old[0 : lenOfOld-1]
	item.Index = -1
	return item
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Elem)
	item.Index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) update(item *Elem, value int, priority int) {
	item.Value = value
	item.Priority = priority
	heap.Fix(pq, item.Index)
}

func main() {
	items := [...]int{5, 3, 9}
	i := 0
	pq := make(PriorityQueue, len(items)) // 创建优先级队列，并初始化
	for _, k := range items {             // 将节点放到优先级队列中
		pq[i] = &Elem{
			Value:    k,
			Priority: k,
			Index:    i}
		i++
	}
	heap.Init(&pq) // 初始化堆
	item := &Elem{ // 创建一个item
		Value: 10,
		Priority: 10,
	}
	heap.Push(&pq, item)           // 入优先级队列
	pq.update(item, item.Value, 6) // 更新item的优先级
	for len(pq) > 0 {
		item := heap.Pop(&pq).(*Elem)
		fmt.Printf("%d:%d index:%d\n", item.Priority, item.Value, item.Index)
	}
}