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