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This commit is contained in:
jiri 2006-03-31 19:01:14 +00:00
parent 8f8b5b855f
commit 5ea385fc30
2 changed files with 142 additions and 3 deletions
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123
bitvector.cc
View File

@ -10,8 +10,131 @@ return s;
istream & operator>>(istream &s, bitvector &x)
{
bool a;
x.copyonwrite();
for(unsigned int i=0; i<x.size(); ++i) {s >>a; x.assign(i,a);}
return s;
}
//implemented so that vectors of different length are considered different automatically
bool bitvector::operator!=(const bitvector &rhs) const
{
if(nn!=rhs.nn || modulo!=rhs.modulo) return 1;
if(v==rhs.v) return 0;
if(!modulo) return memcmp(v,rhs.v,nn*sizeof(bitvector_block));
if(memcmp(v,rhs.v,(nn-1)*sizeof(bitvector_block))) return 1;
bitvector_block a=v[nn-1];
bitvector_block b=rhs.v[nn-1];
//zero out the irrelevant bits
bitvector_block mask= ~((bitvector_block)0);
mask <<=modulo;
mask = ~mask;
a&=mask; b&=mask;
return a!=b;
}
bool bitvector::operator>(const bitvector &rhs) const
{
if(nn!=rhs.nn || modulo!=rhs.modulo) laerror("at the moment only bitvectors of the same length comparable");
if(v==rhs.v) return 0;
if(!modulo) return memcmp(v,rhs.v,nn*sizeof(bitvector_block)>0);
int r;
if((r=memcmp(v,rhs.v,(nn-1)*sizeof(bitvector_block)))) return r>0;
bitvector_block a=v[nn-1];
bitvector_block b=rhs.v[nn-1];
//zero out the irrelevant bits
bitvector_block mask= ~((bitvector_block)0);
mask <<=modulo;
mask = ~mask;
a&=mask; b&=mask;
return a>b;
}
bool bitvector::operator<(const bitvector &rhs) const
{
if(nn!=rhs.nn || modulo!=rhs.modulo) laerror("at the moment only bitvectors of the same length comparable");
if(v==rhs.v) return 0;
if(!modulo) return memcmp(v,rhs.v,nn*sizeof(bitvector_block)<0);
int r;
if((r=memcmp(v,rhs.v,(nn-1)*sizeof(bitvector_block)))) return r<0;
bitvector_block a=v[nn-1];
bitvector_block b=rhs.v[nn-1];
//zero out the irrelevant bits
bitvector_block mask= ~((bitvector_block)0);
mask <<=modulo;
mask = ~mask;
a&=mask; b&=mask;
return a<b;
}
bitvector bitvector::operator~() const
{
bitvector r((*this).size());
for(int i=0; i<nn; ++i) r.v[i] = ~v[i];
return r;
}
bitvector& bitvector::operator&=(const bitvector &rhs)
{
#ifdef DEBUG
if(nn!=rhs.nn || modulo!=rhs.modulo) laerror("operation on incompatible bitvectors");
#endif
copyonwrite();
for(int i=0; i<nn; ++i) v[i] &= rhs.v[i];
return *this;
}
bitvector& bitvector::operator|=(const bitvector &rhs)
{
#ifdef DEBUG
if(nn!=rhs.nn || modulo!=rhs.modulo) laerror("operation on incompatible bitvectors");
#endif
copyonwrite();
for(int i=0; i<nn; ++i) v[i] |= rhs.v[i];
return *this;
}
bitvector& bitvector::operator^=(const bitvector &rhs)
{
#ifdef DEBUG
if(nn!=rhs.nn || modulo!=rhs.modulo) laerror("operation on incompatible bitvectors");
#endif
copyonwrite();
for(int i=0; i<nn; ++i) v[i] ^= rhs.v[i];
return *this;
}
/*number of ones in a binary number, from "Hacker's delight" book*/
#ifdef LONG_IS_32
static unsigned long word_popul(unsigned long x)
{
x -= ((x>>1)&0x55555555);
x = (x&0x33333333) + ((x>>2)&0x33333333);
x=(x + (x>>4))&0x0f0f0f0f;
x+= (x>>8);
x+= (x>>16);
return x&0x3f;
}
#endif
unsigned int bitvector::population(const unsigned int before) const
{
//@@@before
int i;
unsigned int s=0;
for(i=0; i<nn-1; ++i) s+=word_popul(v[i]);
bitvector_block a=v[nn-1];
if(modulo)
{
bitvector_block mask= ~((bitvector_block)0);
mask <<=modulo;
a &= ~mask;
}
return s+word_popul(a);
}

22
bitvector.h
View File

@ -23,7 +23,8 @@ public:
bitvector() : NRVec<bitvector_block>() {};
explicit bitvector (const unsigned int n):NRVec<bitvector_block>((n+blockbits-1)/blockbits) {modulo=n%blockbits;};
bitvector (const bitvector_block a, const unsigned int n):NRVec<bitvector_block>(a,(n+blockbits-1)/blockbits) {modulo=n%blockbits;};
bitvector(const bitvector &rhs) : NRVec<bitvector_block>(rhs) {};
bitvector(const bitvector &rhs) : NRVec<bitvector_block>(rhs) {modulo=rhs.modulo;};
//operator= seems to be correctly synthetized by the compiler
//override dereferencing to address single bits, is however possible
//only in the const context (otherwise we would have to define a type which, when assigned to, changes a single bit - possible but probably inefficient)
void resize(const unsigned int n) {NRVec<bitvector_block>::resize((n+blockbits-1)/blockbits); modulo=n%blockbits;};
@ -36,8 +37,23 @@ public:
const bool assign(const unsigned int i, const bool r) {if(r) set(i); else reset(i); return r;};
void clear() {memset(v,0,nn*sizeof(bitvector_block));};
void fill() {memset(v,0xff,nn*sizeof(bitvector_block));};
const bool operator!=(const bitvector &rhs) const {};
const bool operator==(const bitvector &rhs) const {return !(*this != rhs);};
bool operator!=(const bitvector &rhs) const;
bool operator==(const bitvector &rhs) const {return !(*this != rhs);};
bool operator>(const bitvector &rhs) const;
bool operator<(const bitvector &rhs) const;
bool operator>=(const bitvector &rhs) const {return !(*this < rhs);};
bool operator<=(const bitvector &rhs) const {return !(*this > rhs);};
bitvector operator~() const;
bitvector& operator&=(const bitvector &rhs);
bitvector& operator|=(const bitvector &rhs);
bitvector& operator^=(const bitvector &rhs);
bitvector operator&(const bitvector &rhs) const {return bitvector(*this) &= rhs;};
bitvector operator|(const bitvector &rhs) const {return bitvector(*this) |= rhs;};
bitvector operator^(const bitvector &rhs) const {return bitvector(*this) ^= rhs;};
unsigned int population(const unsigned int before=0) const; //@@@number of 1's
//extended, truncated const i.e. not on *this but return new entity, take care of modulo's bits
//logical shifts <<= >>= << >> not implemented yet
//logical rotations not implemented yet
};