51 lines
918 B
Go
51 lines
918 B
Go
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// Copyright (c) 2012, Matt T. Proud
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// All rights reserved.
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//
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// priority_queue.go provides a simple priority queue.
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package utility
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type Item struct {
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Value interface{}
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Priority int64
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index int
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}
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type PriorityQueue []*Item
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func (q PriorityQueue) Len() int {
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return len(q)
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}
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func (q PriorityQueue) Less(i, j int) bool {
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return q[i].Priority > q[j].Priority
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}
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func (q PriorityQueue) Swap(i, j int) {
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q[i], q[j] = q[j], q[i]
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q[i].index = i
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q[j].index = j
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}
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func (q *PriorityQueue) Push(x interface{}) {
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queue := *q
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size := len(queue)
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queue = queue[0 : size+1]
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item := x.(*Item)
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item.index = size
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queue[size] = item
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*q = queue
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}
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func (q *PriorityQueue) Pop() interface{} {
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queue := *q
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size := len(queue)
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item := queue[size-1]
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item.index = -1
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*q = queue[0 : size-1]
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return item
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}
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