util.cc

关联规则中的频繁项集生成算法genmax

#include "Util.h"
#include <malloc.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include "GArray.h"

#ifdef SGI
/////////Template Instantiation Stuff////////////
#pragma instantiate Util<int>
#pragma instantiate Util<GArray<int> *>
////////////////////////////////////////////////
#endif

int Choose(int n, int k)
{
   int i;
   int val = 1;
 
   if (k >= 0 && k <= n){
      for (i=n; i > n-k; i--)
         val *= i;
      for (i=2; i <= k; i++)
         val /= i;
   }
   
   return val;
}

template <class Items>
boolean Util<Items>::Bsearch(int min, int max, Items *itary, Items it,
                      CMPFUNC cfunc, int& ret)
{
   int mid = (max+min)/2;
   if (max < min) return 0; 
   
   //cout << "MAX " << min  << " " << mid << " " << max << endl << flush;
   int cres = cfunc((void *)&it, (void *) &itary[mid]);
   if (cres == 0){
      if (ret) ret = mid;
      return 1;
   }
   else if (cres < 0) return Bsearch(min, mid-1, itary, it, cfunc, ret);
   else return Bsearch(mid+1, max, itary, it, cfunc, ret);   
}

template <class Items>
int Util<Items>::Realloc (int newlen, int elsz, Items*&ary)
{
   ary = (Items *)::realloc (ary, newlen*elsz);
   if (ary == NULL && newlen != 0){
      perror("REALLOC");
      exit(-1);
   }
   return newlen;
}


#ifdef __GNUC__
/////////Template Instantiation Stuff////////////
template class Util<int>;
template class Util<GArray<int> *>;
#include "Graph.h"
template class Util<GrItem*>;
template class Util<GrNode*>;
class iterstat;
template class Util<iterstat*>;
////////////////////////////////////////////////
#endif