kopia lustrzana https://github.com/onthegomap/planetiler
80 wiersze
2.7 KiB
Java
80 wiersze
2.7 KiB
Java
/*
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* Licensed to GraphHopper GmbH under one or more contributor
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* license agreements. See the NOTICE file distributed with this work for
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* additional information regarding copyright ownership.
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*
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* GraphHopper GmbH licenses this file to you under the Apache License,
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* Version 2.0 (the "License"); you may not use this file except in
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* compliance with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.onthegomap.planetiler.collection;
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/**
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* API for min-heaps that keeps track of {@code int} keys in a range from {@code [0, size)} ordered by {@code long}
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* values.
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* <p>
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* Ported from <a href=
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* "https://github.com/graphhopper/graphhopper/blob/master/core/src/main/java/com/graphhopper/coll/MinHeapWithUpdate.java">GraphHopper</a>
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* and modified to extract a common interface for subclass implementations.
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*/
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public interface LongMinHeap {
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/**
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* Returns a new min-heap where each element has 4 children backed by elements in an array.
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* <p>
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* This is slightly faster than a traditional binary min heap due to a shallower, more cache-friendly memory layout.
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*/
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static LongMinHeap newArrayHeap(int elements) {
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return new ArrayLongMinHeap(elements);
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}
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int size();
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boolean isEmpty();
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/**
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* Adds an element to the heap, the given id must not exceed the size specified in the constructor. Its illegal to
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* push the same id twice (unless it was polled/removed before). To update the value of an id contained in the heap
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* use the {@link #update} method.
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*/
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void push(int id, long value);
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/**
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* @return true if the heap contains an element with the given id
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*/
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boolean contains(int id);
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/**
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* Updates the element with the given id. The complexity of this method is O(log(N)), just like push/poll. Its illegal
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* to update elements that are not contained in the heap. Use {@link #contains} to check the existence of an id.
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*/
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void update(int id, long value);
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/**
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* Updates the weight of the head element in the heap, pushing it down and bubbling up the new min element if
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* necessary.
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*/
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void updateHead(long value);
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/**
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* @return the id of the next element to be polled, i.e. the same as calling poll() without removing the element
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*/
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int peekId();
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long peekValue();
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/**
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* Extracts the element with minimum value from the heap
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*/
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int poll();
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void clear();
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}
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