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Diffstat (limited to 'src/prop/minisat/mtl/BasicHeap.h')
-rw-r--r-- | src/prop/minisat/mtl/BasicHeap.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/prop/minisat/mtl/BasicHeap.h b/src/prop/minisat/mtl/BasicHeap.h new file mode 100644 index 000000000..556d98f84 --- /dev/null +++ b/src/prop/minisat/mtl/BasicHeap.h @@ -0,0 +1,98 @@ +/******************************************************************************************[Heap.h] +MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson + +Permission is hereby granted, free of charge, to any person obtaining a copy of this software and +associated documentation files (the "Software"), to deal in the Software without restriction, +including without limitation the rights to use, copy, modify, merge, publish, distribute, +sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all copies or +substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT +NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, +DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT +OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +**************************************************************************************************/ + +#ifndef BasicHeap_h +#define BasicHeap_h + +#include "Vec.h" + +//================================================================================================= +// A heap implementation with support for decrease/increase key. + + +template<class Comp> +class BasicHeap { + Comp lt; + vec<int> heap; // heap of ints + + // Index "traversal" functions + static inline int left (int i) { return i*2+1; } + static inline int right (int i) { return (i+1)*2; } + static inline int parent(int i) { return (i-1) >> 1; } + + inline void percolateUp(int i) + { + int x = heap[i]; + while (i != 0 && lt(x, heap[parent(i)])){ + heap[i] = heap[parent(i)]; + i = parent(i); + } + heap [i] = x; + } + + + inline void percolateDown(int i) + { + int x = heap[i]; + while (left(i) < heap.size()){ + int child = right(i) < heap.size() && lt(heap[right(i)], heap[left(i)]) ? right(i) : left(i); + if (!lt(heap[child], x)) break; + heap[i] = heap[child]; + i = child; + } + heap[i] = x; + } + + + bool heapProperty(int i) { + return i >= heap.size() + || ((i == 0 || !lt(heap[i], heap[parent(i)])) && heapProperty(left(i)) && heapProperty(right(i))); } + + + public: + BasicHeap(const C& c) : comp(c) { } + + int size () const { return heap.size(); } + bool empty () const { return heap.size() == 0; } + int operator[](int index) const { return heap[index+1]; } + void clear (bool dealloc = false) { heap.clear(dealloc); } + void insert (int n) { heap.push(n); percolateUp(heap.size()-1); } + + + int removeMin() { + int r = heap[0]; + heap[0] = heap.last(); + heap.pop(); + if (heap.size() > 1) percolateDown(0); + return r; + } + + + // DEBUG: consistency checking + bool heapProperty() { + return heapProperty(1); } + + + // COMPAT: should be removed + int getmin () { return removeMin(); } +}; + + +//================================================================================================= +#endif |