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scummvm-cursorfix/engines/crab/PriorityQueue.h
2026-02-02 04:50:13 +01:00

148 lines
4.0 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
/*
* This code is based on the CRAB engine
*
* Copyright (c) Arvind Raja Yadav
*
* Licensed under MIT
*
*/
#ifndef CRAB_PRIORITYQUEUE_H
#define CRAB_PRIORITYQUEUE_H
namespace Crab {
//! \brief The open heap used by all cost-based search algorithms.
//!
//! This class template is basically a thin wrapper on top of both the <code>std::deque</code>
//! class template and the <a href="http://www.sgi.com/tech/stl/">STL</a> heap operations.
template<typename Node>
class PriorityQueue {
Common::Array<Node *> _open;
bool (*compare)(Node const *, Node const *);
public:
//! \brief Constructs a new <code>%PriorityQueue</code> that heap-sorts nodes
//! using the specified comparator.
explicit PriorityQueue(bool (*)(Node const *, Node const *));
//! \brief Returns <code>true</code> if the heap contains no nodes,
//! <code>false</code> otherwise.
bool empty() const;
//! \brief Removes all nodes from the heap.
//!
//! \post
//! - <code>empty()</code>
void clear();
//! \brief Returns the number of nodes currently in the heap.
size_t size() const;
//! \brief Pushes the specified node onto the heap.
//!
//! The heap will maintain the ordering of its nodes during this operation.
//!
//! \post
//! - <code>! empty()</code>
void push(Node *node);
//! \brief Returns the least costly node in the heap.
//!
//! \pre
//! - <code>! empty()</code>
Node *front() const;
//! \brief Removes the least costly node from the heap.
//!
//! The heap will maintain the ordering of its nodes during this operation.
//!
//! \pre
//! - <code>! empty()</code>
void pop();
//! \brief Removes all instances of the specified node from the heap.
void remove(Node const *node);
//! \brief Enumerates all nodes in the heap so far.
//!
//! \param sorted the container to which each node will be added.
//!
//! \pre
//! - There must be no <code>NULL</code> pointers in the heap.
//! \post
//! - All nodes should be sorted by this heap's comparator.
void enumerate(Common::Array<Node const *> &sorted) const;
};
template<typename Node>
PriorityQueue<Node>::PriorityQueue(bool (*c)(Node const *, Node const *)) : _open(), compare(c) {
}
template<typename Node>
bool PriorityQueue<Node>::empty() const {
return _open.empty();
}
template<typename Node>
void PriorityQueue<Node>::clear() {
_open.clear();
}
template<typename Node>
size_t PriorityQueue<Node>::size() const {
return _open.size();
}
template<typename Node>
void PriorityQueue<Node>::push(Node *node) {
_open.insert(Common::upperBound(_open.begin(), _open.end(), node, compare), node);
}
template<typename Node>
Node *PriorityQueue<Node>::front() const {
return _open.back();
}
template<typename Node>
void PriorityQueue<Node>::pop() {
_open.pop_back();
}
template<typename Node>
void PriorityQueue<Node>::remove(Node const *node) {
_open.erase(Common::remove(_open.begin(), _open.end(), node), _open.end());
}
template<typename Node>
void PriorityQueue<Node>::enumerate(Common::Array<Node const *> &sorted) const {
sorted.resize(_open.size());
Common::copy(_open.begin(), _open.end(), sorted.begin());
}
} // End of namespace Crab
#endif // CRAB_PRIORITYQUEUE_H