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@cabloo
Created Jun 17, 2021
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import "container/heap"
type CountPriorityQueueItem struct {
Value, Count, index int
}
type CountPriorityQueue struct {
items []*CountPriorityQueueItem
byValue map[int]*CountPriorityQueueItem
}
func (q *CountPriorityQueue) Pop() interface{} {
last := len(q.items)-1
item := q.items[last]
q.items[last] = nil
q.items = q.items[:last]
return *item
}
func (q *CountPriorityQueue) PopItem() CountPriorityQueueItem {
return heap.Pop(q).(CountPriorityQueueItem)
}
func (q *CountPriorityQueue) Push(x interface{}) {
value := x.(int)
if curr, ok := q.byValue[value]; ok {
curr.Count++
heap.Fix(q, curr.index)
return
}
item := &CountPriorityQueueItem{Value: value, Count: 1, index: len(q.items)}
q.byValue[value] = item
q.items = append(q.items, item)
heap.Fix(q, item.index)
}
func (q CountPriorityQueue) Len() int {
return len(q.items)
}
func (q CountPriorityQueue) Swap(i, j int) {
q.items[i], q.items[j] = q.items[j], q.items[i]
q.items[i].index = i
q.items[j].index = j
}
func (q CountPriorityQueue) Less(a, b int) bool {
return q.items[a].Count >= q.items[b].Count
}
func topKFrequent(nums []int, k int) []int {
maxCountHeap := &CountPriorityQueue{nil, map[int]*CountPriorityQueueItem{}}
for _, v := range nums {
maxCountHeap.Push(v)
}
heap.Init(maxCountHeap)
for _, v := range maxCountHeap.items {
fmt.Println(v.Value, v.Count, v.index)
}
result := []int{}
for ; k > 0; k-- {
result = append(result, maxCountHeap.PopItem().Value)
}
return result
}
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