| /******************************************************************************************[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 |