focus/stack/liststack/stack.go

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2019-07-25 06:30:44 +00:00
package lastack
import (
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"focus/stack"
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"github.com/davecgh/go-spew/spew"
)
type Node struct {
value interface{}
down *Node
}
type Stack struct {
top *Node
size uint
}
func assertImplementation() {
var _ stack.IStack = (*Stack)(nil)
}
func New() *Stack {
s := &Stack{}
s.size = 0
return s
}
func (as *Stack) Clear() {
as.size = 0
as.top = nil
}
func (as *Stack) Empty() bool {
return as.size == 0
}
func (as *Stack) Size() uint {
return as.size
}
// String 从左到右 左边第一个表示Top 如链表 a(top)->b->c
func (as *Stack) String() string {
content := ""
cur := as.top
for ; cur != nil; cur = cur.down {
content += spew.Sprint(cur.value) + " "
}
if len(content) > 0 {
content = content[0 : len(content)-1]
} else {
content = ""
}
return content
}
func (as *Stack) Values() []interface{} {
if as.size == 0 {
return nil
}
result := make([]interface{}, as.size, as.size)
cur := as.top
n := 0
for ; cur != nil; cur = cur.down {
result[n] = cur.value
n++
}
return result
}
func (as *Stack) Push(v interface{}) {
nv := &Node{value: v}
nv.down = as.top
as.top = nv
as.size++
}
func (as *Stack) Pop() (interface{}, bool) {
if as.size == 0 {
return nil, false
}
as.size--
result := as.top
as.top = as.top.down
result.down = nil
return result.value, true
}
func (as *Stack) Peek() (interface{}, bool) {
if as.size == 0 {
return nil, false
}
return as.top.value, true
}