77 lines
2.4 KiB
Go
Executable File
77 lines
2.4 KiB
Go
Executable File
// CookieJar - A contestant's algorithm toolbox
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// Copyright (c) 2013 Peter Szilagyi. All rights reserved.
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//
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// CookieJar is dual licensed: use of this source code is governed by a BSD
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// license that can be found in the LICENSE file. Alternatively, the CookieJar
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// toolbox may be used in accordance with the terms and conditions contained
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// in a signed written agreement between you and the author(s).
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// This is a duplicated and slightly modified version of "gopkg.in/karalabe/cookiejar.v2/collections/prque".
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// Package prque implements a priority queue data structure supporting arbitrary
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// value types and int64 priorities.
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//
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// If you would like to use a min-priority queue, simply negate the priorities.
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//
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// Internally the queue is based on the standard heap package working on a
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// sortable version of the block based stack.
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package prque
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import (
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"cmp"
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"container/heap"
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)
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// Prque is a priority queue data structure.
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type Prque[P cmp.Ordered, V any] struct {
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cont *sstack[P, V]
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}
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// New creates a new priority queue.
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func New[P cmp.Ordered, V any](setIndex SetIndexCallback[V]) *Prque[P, V] {
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return &Prque[P, V]{newSstack[P, V](setIndex)}
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}
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// Push a value with a given priority into the queue, expanding if necessary.
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func (p *Prque[P, V]) Push(data V, priority P) {
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heap.Push(p.cont, &item[P, V]{data, priority})
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}
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// Peek returns the value with the greatest priority but does not pop it off.
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func (p *Prque[P, V]) Peek() (V, P) {
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item := p.cont.blocks[0][0]
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return item.value, item.priority
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}
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// Pop the value with the greatest priority off the stack and returns it.
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// Currently no shrinking is done.
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func (p *Prque[P, V]) Pop() (V, P) {
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item := heap.Pop(p.cont).(*item[P, V])
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return item.value, item.priority
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}
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// PopItem pops only the item from the queue, dropping the associated priority value.
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func (p *Prque[P, V]) PopItem() V {
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return heap.Pop(p.cont).(*item[P, V]).value
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}
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// Remove removes the element with the given index.
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func (p *Prque[P, V]) Remove(i int) V {
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return heap.Remove(p.cont, i).(*item[P, V]).value
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}
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// Empty checks whether the priority queue is empty.
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func (p *Prque[P, V]) Empty() bool {
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return p.cont.Len() == 0
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}
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// Size returns the number of element in the priority queue.
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func (p *Prque[P, V]) Size() int {
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return p.cont.Len()
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}
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// Reset clears the contents of the priority queue.
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func (p *Prque[P, V]) Reset() {
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*p = *New[P, V](p.cont.setIndex)
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}
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