完善: linkedlist

This commit is contained in:
huangsimin
2019-07-19 17:41:28 +08:00
parent 0fad6aae53
commit 76ca4e2a0e
7 changed files with 580 additions and 51 deletions

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@@ -0,0 +1,185 @@
package arraylist
import "log"
type ArrayList struct {
data []interface{}
hidx uint // [ nil(hdix) 1 nil(tidx) ]
tidx uint
size uint
growthSize uint
shrinkSize uint
}
const (
listMaxLimit = uint(1) << 63
listMinLimit = uint(8)
initCap = uint(8)
//growthFactor = float32(2.0) // growth by 100%
//shrinkFactor = float32(0.25) // shrink when size is 25% of capacity (0 means never shrink)
)
func New() *ArrayList {
l := &ArrayList{}
l.data = make([]interface{}, initCap, initCap)
l.tidx = initCap / 2
l.hidx = l.tidx - 1
return l
}
func (l *ArrayList) Clear() {
l.data = make([]interface{}, 8, 8)
l.tidx = initCap / 2
l.hidx = l.tidx - 1
l.size = 0
}
func (l *ArrayList) Empty() bool {
return l.size == 0
}
func (l *ArrayList) Size() uint {
return l.size
}
func (l *ArrayList) shrink() {
if l.size <= listMinLimit {
return
}
if l.size <= l.shrinkSize {
nSize := l.shrinkSize - l.shrinkSize>>1
temp := make([]interface{}, nSize, nSize)
ghidx := l.size / 2
gtidx := ghidx + l.size + 1
copy(temp[ghidx+1:], l.data[l.hidx+1:l.tidx])
l.data = temp
l.hidx = ghidx
l.tidx = gtidx
}
}
// 后续需要优化 growth 策略
func (l *ArrayList) growth() {
if l.size >= listMaxLimit {
log.Panic("list size is over listMaxLimit", listMaxLimit)
}
lcap := uint(len(l.data))
nSize := lcap << 1
temp := make([]interface{}, nSize, nSize)
ghidx := lcap / 2
gtidx := ghidx + l.size + 1
copy(temp[ghidx+1:], l.data[l.hidx+1:l.tidx])
l.data = temp
l.hidx = ghidx
l.tidx = gtidx
}
func (l *ArrayList) PushFront(values ...interface{}) {
psize := uint(len(values))
for l.hidx+1-psize > listMaxLimit {
l.growth()
// panic("growth -1")
}
for _, v := range values {
l.data[l.hidx] = v
l.hidx--
}
l.size += psize
}
func (l *ArrayList) PushBack(values ...interface{}) {
psize := uint(len(values))
for l.tidx+psize > uint(len(l.data)) { // [0 1 2 3 4 5 6]
l.growth()
}
for _, v := range values {
l.data[l.tidx] = v
l.tidx++
}
l.size += psize
}
func (l *ArrayList) PopFront() (result interface{}, found bool) {
if l.size != 0 {
l.size--
l.hidx++
return l.data[l.hidx], true
}
return nil, false
}
func (l *ArrayList) PopBack() (result interface{}, found bool) {
if l.size != 0 {
l.size--
l.tidx--
return l.data[l.tidx], true
}
return nil, false
}
func (l *ArrayList) Index(idx uint) (interface{}, bool) {
if idx < l.size {
return l.data[idx+l.hidx+1], true
}
return nil, false
}
func (l *ArrayList) Remove(idx uint) (result interface{}, isfound bool) {
if idx >= l.size {
return nil, false
}
offset := l.hidx + 1 + idx
isfound = true
result = l.data[offset]
// l.data[offset] = nil // cleanup reference
if l.size-l.tidx > l.hidx {
copy(l.data[offset:], l.data[offset+1:l.tidx]) // shift to the left by one (slow operation, need ways to optimize this)
l.tidx--
} else {
copy(l.data[l.hidx+2:], l.data[l.hidx+1:offset])
l.hidx++
}
l.size--
l.shrink()
return
}
func (l *ArrayList) Contains(values ...interface{}) bool {
for _, searchValue := range values {
found := false
for _, element := range l.data[l.hidx+1 : l.tidx] {
if element == searchValue {
found = true
break
}
}
if !found {
return false
}
}
return true
}
func (l *ArrayList) Values() []interface{} {
newElements := make([]interface{}, l.size, l.size)
copy(newElements, l.data[l.hidx+1:l.tidx])
return newElements
}

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@@ -0,0 +1,171 @@
package arraylist
import (
"bytes"
"encoding/gob"
"io/ioutil"
"log"
"testing"
"github.com/davecgh/go-spew/spew"
)
func TestPush(t *testing.T) {
l := New()
for i := 0; i < 2; i++ {
l.PushFront(1)
}
var result string
result = spew.Sprint(l.Values())
if result != "[1 1]" {
t.Error(result)
}
for i := 0; i < 2; i++ {
l.PushBack(2)
}
result = spew.Sprint(l.Values())
if result != "[1 1 2 2]" {
t.Error(result)
}
}
func TestGrowth(t *testing.T) {
l := New()
for i := 0; i < 5; i++ {
l.PushFront(1)
}
var result string
result = spew.Sprint(l.Values())
if result != "[1 1 1 1 1]" {
t.Error(result)
}
l = New()
for i := 0; i < 7; i++ {
l.PushBack(1)
}
result = spew.Sprint(l.Values())
if result != "[1 1 1 1 1 1 1]" {
t.Error(result)
}
// for i := 0; i < 2; i++ {
// l.PushBack(2)
// }
// result = spew.Sprint(l.Values())
// if result != "[1 1 2 2]" {
// t.Error(result)
// }
}
func TestPop(t *testing.T) {
l := New()
for i := 0; i < 5; i++ {
l.PushFront(i)
}
for i := 4; i >= 0; i-- {
if v, ok := l.PopFront(); ok {
if v != i {
t.Error("should be ", v)
}
} else {
t.Error("should be ok, value is", v)
}
}
if v, ok := l.PopFront(); ok {
t.Error("should not be ok, v = ", v)
}
for i := 0; i < 5; i++ {
l.PushFront(i)
}
for i := 0; i < 5; i++ {
if v, ok := l.PopBack(); ok {
if v != i {
t.Error("should be ", v)
}
} else {
t.Error("should be ok, value is", v)
}
}
if v, ok := l.PopBack(); ok {
t.Error("should not be ok, v = ", v)
}
}
func TestRemove(t *testing.T) {
l := New()
for i := 0; i < 5; i++ {
l.PushFront(uint(i))
}
var result string
for _, selval := range []uint{4, 3} {
last, _ := l.Index(selval)
if v, isfound := l.Remove(selval); isfound {
if v != last {
t.Error(v, " != ", last)
}
} else {
t.Error("should be found")
}
}
result = spew.Sprint(l.Values())
if result != "[4 3 2]" {
t.Error("should be [4 3 2], value =", result)
}
v, _ := l.Remove(1)
if v != uint(3) {
t.Error(v)
}
v, _ = l.Remove(1)
if v != uint(2) {
t.Error(v)
}
v, _ = l.Remove(1)
if v != nil && l.Size() != 1 {
t.Error(v)
}
v, _ = l.Remove(0)
if v != uint(4) && l.Size() != 0 {
t.Error(v, "size = ", l.Size())
}
}
func loadTestData() []int {
data, err := ioutil.ReadFile("../../l.log")
if err != nil {
log.Println(err)
}
var l []int
decoder := gob.NewDecoder(bytes.NewReader(data))
decoder.Decode(&l)
return l
}
func BenchmarkPush(b *testing.B) {
l := loadTestData()
b.N = len(l)
arr := New()
for i := 0; i < b.N; i++ {
arr.PushBack(l[i])
}
}