Ifpack2 Templated Preconditioning Package Version 1.0
Ifpack2_Heap.hpp
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00004 //       Ifpack2: Tempated Object-Oriented Algebraic Preconditioner Package
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00042 
00043 #ifndef IFPACK2_HEAP_HPP
00044 #define IFPACK2_HEAP_HPP
00045 
00046 #include <algorithm>
00047 #include "Teuchos_Array.hpp"
00048 
00049 namespace Ifpack2 {
00050 
00051 template<typename Scalar, typename Ordinal>
00052 struct greater_indirect {
00053   greater_indirect(const Teuchos::Array<Scalar>& vals)
00054   : m_vals(vals) {}
00055   ~greater_indirect(){}
00056 
00057   bool operator()(const Ordinal& lhs, const Ordinal& rhs) const
00058   { return Teuchos::ScalarTraits<Scalar>::magnitude(m_vals[lhs]) >
00059            Teuchos::ScalarTraits<Scalar>::magnitude(m_vals[rhs]); }
00060 
00061 private:
00062   const Teuchos::Array<Scalar>& m_vals;
00063 };//struct greater_indirect
00064 
00065 
00068 template<typename Ordinal, typename SizeType>
00069 void add_to_heap(const Ordinal& idx, Teuchos::Array<Ordinal>& heap, SizeType& heap_len)
00070 {
00071   if (heap.size() == heap_len) heap.push_back(idx);
00072   else heap[heap_len] = idx;
00073   ++heap_len;
00074   std::push_heap(heap.begin(), heap.begin()+heap_len, std::greater<Ordinal>());
00075 }
00076 
00080 template<typename Ordinal, typename SizeType, class Compare>
00081 void add_to_heap(const Ordinal& idx, Teuchos::Array<Ordinal>& heap, SizeType& heap_len, Compare comp)
00082 {
00083   if (heap.size() == heap_len) heap.push_back(idx);
00084   else heap[heap_len] = idx;
00085   ++heap_len;
00086   std::push_heap(heap.begin(), heap.begin()+heap_len, comp);
00087 }
00088 
00090 template<typename Ordinal, typename SizeType>
00091 void rm_heap_root(Teuchos::Array<Ordinal>& heap, SizeType& heap_len)
00092 {
00093   std::pop_heap(heap.begin(), heap.begin()+heap_len, std::greater<Ordinal>());
00094   --heap_len;
00095 }
00096 
00100 template<typename Ordinal, typename SizeType, class Compare>
00101 void rm_heap_root(Teuchos::Array<Ordinal>& heap, SizeType& heap_len, Compare comp)
00102 {
00103   std::pop_heap(heap.begin(), heap.begin()+heap_len, comp);
00104   --heap_len;
00105 }
00106 
00107 }//namespace Ifpack2
00108 
00109 #endif
00110 
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