在Go中偷看优先级队列的顶部？

import "container/heap"

type Item struct {
    value    interface{} // 元素值
    priority int         // 优先级
    index    int         // 元素在队列中的索引
}

type PriorityQueue []*Item

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

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

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

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

func (pq *PriorityQueue) Pop() interface{} {
    old := *pq
    n := len(old)
    item := old[n-1]
    item.index = -1 // 标记已移除
    *pq = old[0 : n-1]
    return item
}

pq := make(PriorityQueue, 0)
heap.Init(&pq)

item := &Item{
    value:    "element",
    priority: 1,
}
heap.Push(&pq, item)

top := pq[0]

package main

import (
    "container/heap"
    "fmt"
)

type Item struct {
    value    interface{} // 元素值
    priority int         // 优先级
    index    int         // 元素在队列中的索引
}

type PriorityQueue []*Item

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

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

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

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

func (pq *PriorityQueue) Pop() interface{} {
    old := *pq
    n := len(old)
    item := old[n-1]
    item.index = -1 // 标记已移除
    *pq = old[0 : n-1]
    return item
}

func main() {
    pq := make(PriorityQueue, 0)
    heap.Init(&pq)

    item1 := &Item{
        value:    "element1",
        priority: 3,
    }
    heap.Push(&pq, item1)

    item2 := &Item{
        value:    "element2",
        priority: 1,
    }
    heap.Push(&pq, item2)

    item3 := &Item{
        value:    "element3",
        priority: 2,
    }
    heap.Push(&pq, item3)

    top := pq[0]
    fmt.Println("Top element:", top.value)
}