54 lines
851 B
Go
54 lines
851 B
Go
package queue
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type Queue[T any] interface {
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Enqueue(T)
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Dequeue() T
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Size() int
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IsEmpty() bool
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}
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// We use linked list as internal data structure
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// to get O(1) speed for push and pop opeartions
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type node[Item any] struct {
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item Item
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next *node[Item]
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}
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type queue[OfType any] struct {
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size int
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head *node[OfType]
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tail *node[OfType]
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}
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func NewQueue[OfType any]() Queue[OfType] {
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return &queue[OfType]{}
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}
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func (q *queue[T]) Enqueue(item T) {
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oldTail := q.tail
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q.tail = &node[T]{item: item, next: nil}
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if q.IsEmpty() {
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q.head = q.tail
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} else {
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oldTail.next = q.tail
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}
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q.size++
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}
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func (q *queue[T]) Dequeue() T {
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first := q.head
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q.head = q.head.next
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if q.IsEmpty() {
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q.tail = nil
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}
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q.size--
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return first.item
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}
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func (q *queue[T]) Size() int {
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return q.size
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}
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func (q *queue[T]) IsEmpty() bool {
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return q.head == nil
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}
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