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secondo/Algebras/MainMemory2/MemoryVectorObject.cpp
2026-01-23 17:03:45 +08:00

125 lines
2.5 KiB
C++

/*
----
This file is part of SECONDO.
Copyright (C) 2016,
University in Hagen,
Faculty of Mathematics and Computer Science,
Database Systems for New Applications.
SECONDO is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
SECONDO is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
----
*/
#include "MemoryVectorObject.h"
#include <vector>
namespace mm2algebra{
bool MemoryVectorObject::checkSorted() {
sorted = true;
if(v->size() < 2u){
return true;
}
for(size_t i=0;i<v->size()-1; i++){
if(v->at(i)->Compare((*v)[i+1]) > 0){
sorted = false;
return false;
}
}
return true;
}
void reheap(std::vector<Attribute*>& heap,int i, int k){
int j,son;
j=i;
bool done = false;
while(2*j<=k && !done){
if(2*j+1<=k){
if(heap[2*j-1]->Compare(heap[2*j])>0){
son = 2*j;
} else {
son = 2*j+1;
}
} else {
son = 2*j;
}
if(heap[j-1]->Compare(heap[son-1])<0){
Attribute* tmp = heap[j-1];
heap[j-1] = heap[son-1];
heap[son-1] = tmp;
j = son;
} else {
done=true;
}
}
}
void heapSort(std::vector<Attribute*>& v){
size_t n = v.size();
for(size_t i = n/2; i>0 ; i--){
reheap(v,i,n);
}
for(size_t i=n;i>1;i--){
Attribute* tmp = v[0];
v[0] = v[i-1];
v[i-1] = tmp;
reheap(v,1,i-1);
}
}
void MemoryVectorObject::sort(){
if(sorted) return;
heapSort(*v);
sorted=true;
}
int MemoryVectorObject::binSearch(const Attribute* a) const{
if(!sorted) return -1;
if(v->empty()){
return 0;
}
size_t min = 0;
size_t max = v->size()-1;
while(min<max){
size_t mid = (min + max)/2;
int c = v->at(mid)->Compare(a);
if(c==0) return mid; // found element
if(c<0){
min = mid + 1;
} else {
max = mid - 1;
}
}
// now holds min == max
int c = v->at(min)->Compare(a);
return c < 0 ? min+1:min;
}
}