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authorStephen Hines <srhines@google.com>2019-07-02 16:25:20 -0700
committerAli B <abittin@gmail.com>2019-07-05 19:33:16 +0300
commit9afee4e65dc5f9f5eb371683729ff67b8df81d03 (patch)
tree4cf241d6c9044f91ee8c06e6920174d06f8de0b6 /clang-r353983e/include/llvm/ADT/PriorityQueue.h
parent2f19bd722c4c825320d1511c1ed83161b7f95d51 (diff)
Update prebuilt Clang to r353983e.HEADq10.0
clang 9.0.5 (based on r353983e) from build 5696680. Bug: http://b/135931688 Bug: http://b/136008926 Test: N/A Change-Id: I922d17410047d2e2df4625615352c588ee71b203
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+//===- llvm/ADT/PriorityQueue.h - Priority queues ---------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the PriorityQueue class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_PRIORITYQUEUE_H
+#define LLVM_ADT_PRIORITYQUEUE_H
+
+#include <algorithm>
+#include <queue>
+
+namespace llvm {
+
+/// PriorityQueue - This class behaves like std::priority_queue and
+/// provides a few additional convenience functions.
+///
+template<class T,
+ class Sequence = std::vector<T>,
+ class Compare = std::less<typename Sequence::value_type> >
+class PriorityQueue : public std::priority_queue<T, Sequence, Compare> {
+public:
+ explicit PriorityQueue(const Compare &compare = Compare(),
+ const Sequence &sequence = Sequence())
+ : std::priority_queue<T, Sequence, Compare>(compare, sequence)
+ {}
+
+ template<class Iterator>
+ PriorityQueue(Iterator begin, Iterator end,
+ const Compare &compare = Compare(),
+ const Sequence &sequence = Sequence())
+ : std::priority_queue<T, Sequence, Compare>(begin, end, compare, sequence)
+ {}
+
+ /// erase_one - Erase one element from the queue, regardless of its
+ /// position. This operation performs a linear search to find an element
+ /// equal to t, but then uses all logarithmic-time algorithms to do
+ /// the erase operation.
+ ///
+ void erase_one(const T &t) {
+ // Linear-search to find the element.
+ typename Sequence::size_type i = find(this->c, t) - this->c.begin();
+
+ // Logarithmic-time heap bubble-up.
+ while (i != 0) {
+ typename Sequence::size_type parent = (i - 1) / 2;
+ this->c[i] = this->c[parent];
+ i = parent;
+ }
+
+ // The element we want to remove is now at the root, so we can use
+ // priority_queue's plain pop to remove it.
+ this->pop();
+ }
+
+ /// reheapify - If an element in the queue has changed in a way that
+ /// affects its standing in the comparison function, the queue's
+ /// internal state becomes invalid. Calling reheapify() resets the
+ /// queue's state, making it valid again. This operation has time
+ /// complexity proportional to the number of elements in the queue,
+ /// so don't plan to use it a lot.
+ ///
+ void reheapify() {
+ std::make_heap(this->c.begin(), this->c.end(), this->comp);
+ }
+
+ /// clear - Erase all elements from the queue.
+ ///
+ void clear() {
+ this->c.clear();
+ }
+};
+
+} // End llvm namespace
+
+#endif