stl-go/heap/heap.go
2022-05-03 18:52:56 +08:00

91 lines
1.6 KiB
Go

/*
* @Author: NorthCity1984
* @LastEditTime: 2022-04-27 13:19:36
* @Description:
* @Website: https://grimoire.cn
* Copyright (c) NorthCity1984 All rights reserved.
*/
package heap
type Number interface {
int | int64 | float32 | float64
}
type heap[T Number] struct {
array []T
len int
cmp func(T, T) bool
}
// 返回对应类型的零值
func zeroValue[T Number]() (value T) { return }
func (h *heap[T]) up(x int) {
for x > 1 && h.cmp(h.array[x], h.array[x/2]) {
h.array[x], h.array[x/2] = h.array[x/2], h.array[x]
x /= 2
}
}
func (h *heap[T]) down(x int) {
for x*2 <= h.len {
t := x * 2
if t+1 <= h.len && h.cmp(h.array[t+1], h.array[t]) {
t++
}
if !h.cmp(h.array[t], h.array[x]) {
break
}
h.array[x], h.array[t] = h.array[t], h.array[x]
x = t
}
}
func (h *heap[T]) Push(v T) {
h.array = append(h.array, v)
h.len++
h.up(h.len)
}
func (h *heap[T]) Pop() T {
if h.len == 0 {
return zeroValue[T]()
}
ret := h.array[1]
h.array[1], h.array[h.len] = h.array[h.len], h.array[1]
h.array = h.array[:h.len]
h.len--
h.down(1)
return ret
}
func (h *heap[T]) Top() T {
return h.array[1]
}
func Init[T Number](array []T, cmp func(T, T) bool) heap[T] {
newArray := make([]T, len(array)+1)
copy(newArray[1:], array)
h := heap[T]{
array: newArray,
len: len(array),
cmp: cmp,
}
for i := h.len; i >= 1; i-- {
h.down(i)
}
return h
}
func MaxHeap[T Number]() func(T, T) bool {
return func(t1, t2 T) bool {
return t1 > t2
}
}
func MinHeap[T Number]() func(T, T) bool {
return func(t1, t2 T) bool {
return t1 < t2
}
}