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mintzhaomintzhao
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add arrayStack & linkedListStack
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‎stacks/arrayStack.go

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// Copyright 2015 mint.zhao.chiu@gmail.com
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//
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// Licensed under the Apache License, Version 2.0 (the "License"): you may
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// not use this file except in compliance with the License. You may obtain
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// a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations
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// under the License.
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package stacks
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import (
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"fmt"
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"github.com/aiwuTech/container/lists"
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"strings"
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)
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type ArrayStack struct {
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list *lists.ArrayList
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}
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func NewArrayStack() *ArrayStack {
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return &ArrayStack{
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list: lists.NewArrayList(),
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}
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}
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// Pushes a value onto the top of the stack
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func (stack *ArrayStack) Push(value interface{}) {
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stack.list.Add(value)
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}
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// Pops (removes) top element on stack and returns it, or nil if stack is empty.
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// Second return parameter is true, unless the stack was empty and there was nothing to pop.
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func (stack *ArrayStack) Pop() (value interface{}, ok bool) {
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value, ok = stack.list.Get(stack.list.Len() - 1)
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stack.list.Remove(stack.list.Len() - 1)
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return
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}
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// Returns top element on the stack without removing it, or nil if stack is empty.
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// Second return parameter is true, unless the stack was empty and there was nothing to peek.
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func (stack *ArrayStack) Peek() (value interface{}, ok bool) {
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return stack.list.Get(stack.list.Len() - 1)
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}
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// Returns true if stack does not contain any elements.
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func (stack *ArrayStack) Empty() bool {
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return stack.list.Empty()
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}
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// Returns number of elements within the stack.
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func (stack *ArrayStack) Len() int {
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return stack.list.Len()
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}
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// Removes all elements from the stack.
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func (stack *ArrayStack) Clear() {
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stack.list.Clear()
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}
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// Returns all elements in the stack (LIFO order).
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func (stack *ArrayStack) Elements() []interface{} {
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size := stack.list.Len()
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elements := make([]interface{}, size, size)
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for i := 1; i <= size; i++ {
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elements[size-i], _ = stack.list.Get(i - 1) // in reverse (LIFO)
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}
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return elements
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}
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func (stack *ArrayStack) String() string {
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str := "ArrayStack{ "
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values := []string{}
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for _, value := range stack.list.Elements() {
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values = append(values, fmt.Sprintf("%v", value))
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}
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str += strings.Join(values, ", ")
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str += " }"
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return str
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}
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// not important, just for interface{}
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func (stack *ArrayStack) Contains(elements ...interface{}) bool {
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return stack.list.Contains(elements...)
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}

‎stacks/arrayStock_test.go

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// Copyright 2015 mint.zhao.chiu@gmail.com
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//
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// Licensed under the Apache License, Version 2.0 (the "License"): you may
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// not use this file except in compliance with the License. You may obtain
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// a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations
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// under the License.
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package stacks
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import (
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"testing"
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)
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func TestArrayStack(t *testing.T) {
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stack := NewArrayStack()
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if actualValue := stack.Empty(); actualValue != true {
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t.Errorf("Got %v expected %v", actualValue, true)
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}
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// insertions
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stack.Push(1)
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stack.Push(2)
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stack.Push(3)
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if actualValue := stack.Elements(); actualValue[0].(int) != 3 || actualValue[1].(int) != 2 || actualValue[2].(int) != 1 {
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t.Errorf("Got %v expected %v", actualValue, "[3,2,1]")
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}
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if actualValue := stack.Empty(); actualValue != false {
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t.Errorf("Got %v expected %v", actualValue, false)
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}
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if actualValue := stack.Len(); actualValue != 3 {
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t.Errorf("Got %v expected %v", actualValue, 3)
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}
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if actualValue, ok := stack.Peek(); actualValue != 3 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 3)
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}
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stack.Pop()
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if actualValue, ok := stack.Peek(); actualValue != 2 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 2)
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}
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if actualValue, ok := stack.Pop(); actualValue != 2 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 2)
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}
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if actualValue, ok := stack.Pop(); actualValue != 1 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 1)
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}
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if actualValue, ok := stack.Pop(); actualValue != nil || ok {
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t.Errorf("Got %v expected %v", actualValue, nil)
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}
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if actualValue := stack.Empty(); actualValue != true {
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t.Errorf("Got %v expected %v", actualValue, true)
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}
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if actualValue := stack.Elements(); len(actualValue) != 0 {
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t.Errorf("Got %v expected %v", actualValue, "[]")
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}
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}
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func BenchmarkArrayStack(b *testing.B) {
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for i := 0; i < b.N; i++ {
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stack := NewArrayStack()
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for n := 0; n < 1000; n++ {
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stack.Push(i)
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}
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for !stack.Empty() {
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stack.Pop()
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}
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}
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}

‎stacks/linkedListStack.go

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// Copyright 2015 mint.zhao.chiu@gmail.com
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//
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// Licensed under the Apache License, Version 2.0 (the "License"): you may
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// not use this file except in compliance with the License. You may obtain
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// a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations
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// under the License.
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package stacks
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import (
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"fmt"
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"github.com/aiwuTech/container/lists"
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"strings"
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)
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type LinkedListStack struct {
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list *lists.SinglyLinkedList
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}
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// Instantiates a new empty stack
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func NewLinkedListStack() *LinkedListStack {
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return &LinkedListStack{
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list: lists.NewSinglyLinkedList(),
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}
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}
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// Pushes a value onto the top of the stack
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func (stack *LinkedListStack) Push(value interface{}) {
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stack.list.Prepend(value)
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}
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// Pops (removes) top element on stack and returns it, or nil if stack is empty.
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// Second return parameter is true, unless the stack was empty and there was nothing to pop.
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func (stack *LinkedListStack) Pop() (value interface{}, ok bool) {
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value, ok = stack.list.Get(0)
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stack.list.Remove(0)
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return
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}
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// Returns top element on the stack without removing it, or nil if stack is empty.
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// Second return parameter is true, unless the stack was empty and there was nothing to peek.
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func (stack *LinkedListStack) Peek() (value interface{}, ok bool) {
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return stack.list.Get(0)
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}
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// Returns true if stack does not contain any elements.
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func (stack *LinkedListStack) Empty() bool {
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return stack.list.Empty()
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}
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// Returns number of elements within the stack.
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func (stack *LinkedListStack) Len() int {
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return stack.list.Len()
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}
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// Removes all elements from the stack.
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func (stack *LinkedListStack) Clear() {
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stack.list.Clear()
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}
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// Returns all elements in the stack (LIFO order).
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func (stack *LinkedListStack) Elements() []interface{} {
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return stack.list.Elements()
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}
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func (stack *LinkedListStack) String() string {
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str := "LinkedListStack{ "
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values := []string{}
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for _, value := range stack.list.Elements() {
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values = append(values, fmt.Sprintf("%v", value))
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}
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str += strings.Join(values, ", ")
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str += " }"
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return str
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}
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// not important, just for interface{}
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func (stack *LinkedListStack) Contains(elements ...interface{}) bool {
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return stack.list.Contains(elements...)
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}

‎stacks/linkedListStack_test.go

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// Copyright 2015 mint.zhao.chiu@gmail.com
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//
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// Licensed under the Apache License, Version 2.0 (the "License"): you may
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// not use this file except in compliance with the License. You may obtain
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// a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations
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// under the License.
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package stacks
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import "testing"
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func TestLinkedListStack(t *testing.T) {
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stack := NewLinkedListStack()
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if actualValue := stack.Empty(); actualValue != true {
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t.Errorf("Got %v expected %v", actualValue, true)
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}
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// insertions
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stack.Push(1)
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stack.Push(2)
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stack.Push(3)
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if actualValue := stack.Elements(); actualValue[0].(int) != 3 || actualValue[1].(int) != 2 || actualValue[2].(int) != 1 {
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t.Errorf("Got %v expected %v", actualValue, "[3,2,1]")
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}
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if actualValue := stack.Empty(); actualValue != false {
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t.Errorf("Got %v expected %v", actualValue, false)
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}
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if actualValue := stack.Len(); actualValue != 3 {
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t.Errorf("Got %v expected %v", actualValue, 3)
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}
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if actualValue, ok := stack.Peek(); actualValue != 3 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 3)
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}
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stack.Pop()
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if actualValue, ok := stack.Peek(); actualValue != 2 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 2)
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}
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if actualValue, ok := stack.Pop(); actualValue != 2 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 2)
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}
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if actualValue, ok := stack.Pop(); actualValue != 1 || !ok {
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t.Errorf("Got %v expected %v", actualValue, 1)
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}
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if actualValue, ok := stack.Pop(); actualValue != nil || ok {
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t.Errorf("Got %v expected %v", actualValue, nil)
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}
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if actualValue := stack.Empty(); actualValue != true {
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t.Errorf("Got %v expected %v", actualValue, true)
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}
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if actualValue := stack.Elements(); len(actualValue) != 0 {
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t.Errorf("Got %v expected %v", actualValue, "[]")
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}
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}
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func BenchmarkLinkedListStack(b *testing.B) {
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for i := 0; i < b.N; i++ {
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stack := NewLinkedListStack()
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for n := 0; n < 1000; n++ {
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stack.Push(i)
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}
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for !stack.Empty() {
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stack.Pop()
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}
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}
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}

‎stacks/stack.go

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// Copyright 2015 mint.zhao.chiu@gmail.com
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//
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// Licensed under the Apache License, Version 2.0 (the "License"): you may
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// not use this file except in compliance with the License. You may obtain
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// a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11+
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations
13+
// under the License.
14+
package stacks
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import "github.com/aiwuTech/container"
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type StackInterface interface {
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Push(value interface{})
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Pop() (value interface{}, ok bool)
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Peek() (value interface{}, ok bool)
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container.ContainerInterface
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}

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