heap.go

package godata

import "container/heap"

type MinHeap []int

func (h MinHeap) Len() int           { return len(h) }
func (h MinHeap) Less(i, j int) bool { return h[i] < h[j] }
func (h MinHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *MinHeap) Push(x interface{}) {
	// Push and Pop use pointer receivers because they modify the slice's length,
	// not just its contents.
	*h = append(*h, x.(int))
}

func (h *MinHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}


func PopMin(m *MinHeap) int{
	if m.Len() > 0 {
		heap.Init(m)
		return heap.Pop(m).(int)
	}
	return -1
}
func PushMin(m *MinHeap,value int){
	heap.Init(m)
	heap.Push(m,value)
}
func TopMin(m *MinHeap)int {
	heap.Init(m)
	value := heap.Pop(m)
	heap.Push(m,value)
	return value.(int)
}