76 lines
1.1 KiB
Go
76 lines
1.1 KiB
Go
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// Package stack provides a thread-safe LIFO stack implementation.
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package stack
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import "sync"
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type Stack[T any] interface {
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Push(item T)
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Peek() (T, bool)
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Pop() (T, bool)
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IsEmpty() bool
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Size() int
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}
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type stack[T any] struct {
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items []T
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lock sync.Mutex
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}
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func New[T any]() Stack[T] {
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return &stack[T]{items: []T{}}
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}
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func (s *stack[T]) Push(item T) {
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s.lock.Lock()
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defer s.lock.Unlock()
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s.items = append(s.items, item)
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}
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func (s *stack[T]) Pop() (T, bool) {
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s.lock.Lock()
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defer s.lock.Unlock()
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length := len(s.items)
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if len(s.items) == 0 {
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var zero T
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return zero, false
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}
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lastItemIndex := length - 1
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item := s.items[lastItemIndex]
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s.items = s.items[:lastItemIndex]
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return item, true
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}
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func (s *stack[T]) Peek() (T, bool) {
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s.lock.Lock()
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defer s.lock.Unlock()
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length := len(s.items)
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if len(s.items) == 0 {
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var zero T
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return zero, false
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}
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lastItemIndex := length - 1
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item := s.items[lastItemIndex]
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return item, true
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}
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func (s *stack[T]) IsEmpty() bool {
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s.lock.Lock()
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defer s.lock.Unlock()
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return len(s.items) == 0
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}
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func (s *stack[T]) Size() int {
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s.lock.Lock()
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defer s.lock.Unlock()
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return len(s.items)
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}
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