mirror of
https://github.com/emirpasic/gods
synced 2024-11-08 13:10:26 +00:00
106 lines
3.3 KiB
Go
106 lines
3.3 KiB
Go
/*
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Copyright (c) 2015, Emir Pasic
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice, this
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list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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// Implementation of stack backed by ArrayList.
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// Structure is not thread safe.
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// References: http://en.wikipedia.org/wiki/Stack_%28abstract_data_type%29
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package arraystack
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import (
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"fmt"
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"github.com/emirpasic/gods/lists/arraylist"
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"github.com/emirpasic/gods/stacks"
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"strings"
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)
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func assertInterfaceImplementation() {
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var _ stacks.Interface = (*Stack)(nil)
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}
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type Stack struct {
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list *arraylist.List
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}
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// Instantiates a new empty stack
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func New() *Stack {
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return &Stack{list: arraylist.New()}
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}
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// Pushes a value onto the top of the stack
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func (stack *Stack) 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 *Stack) Pop() (value interface{}, ok bool) {
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value, ok = stack.list.Get(stack.list.Size() - 1)
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stack.list.Remove(stack.list.Size() - 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 *Stack) Peek() (value interface{}, ok bool) {
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return stack.list.Get(stack.list.Size() - 1)
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}
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// Returns true if stack does not contain any elements.
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func (stack *Stack) 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 *Stack) Size() int {
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return stack.list.Size()
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}
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// Removes all elements from the stack.
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func (stack *Stack) 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 *Stack) Values() []interface{} {
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size := stack.list.Size()
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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 *Stack) String() string {
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str := "ArrayStack\n"
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values := []string{}
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for _, value := range stack.list.Values() {
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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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return str
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}
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