90 lines
2.0 KiB
Plaintext
90 lines
2.0 KiB
Plaintext
@q $Id: tl_static.cweb 200 2005-05-12 12:28:19Z kamenik $ @>
|
|
@q Copyright 2004, Ondra Kamenik @>
|
|
|
|
@ Start of {\tt tl\_static.cpp} file.
|
|
@c
|
|
#include "tl_static.h"
|
|
#include "tl_exception.h"
|
|
|
|
TLStatic tls;
|
|
@<|TLStatic| methods@>;
|
|
@<|PascalTriangle| constructor code@>;
|
|
@<|PascalTriangle::noverk| code@>;
|
|
|
|
@ Note that we allow for repeated calls of |init|. This is not normal
|
|
and the only purpose of allowing this is the test suite.
|
|
|
|
@<|TLStatic| methods@>=
|
|
TLStatic::TLStatic()
|
|
{
|
|
ebundle = NULL;
|
|
pbundle = NULL;
|
|
ptriang = NULL;
|
|
}
|
|
|
|
TLStatic::~TLStatic()
|
|
{
|
|
if (ebundle)
|
|
delete ebundle;
|
|
if (pbundle)
|
|
delete pbundle;
|
|
if (ptriang)
|
|
delete ptriang;
|
|
}
|
|
|
|
void TLStatic::init(int dim, int nvar)
|
|
{
|
|
if (ebundle)
|
|
ebundle->generateUpTo(dim);
|
|
else
|
|
ebundle = new EquivalenceBundle(dim);
|
|
|
|
if (pbundle)
|
|
pbundle->generateUpTo(dim);
|
|
else
|
|
pbundle = new PermutationBundle(dim);
|
|
|
|
if (ptriang)
|
|
delete ptriang;
|
|
ptriang = new PascalTriangle(nvar, dim);
|
|
}
|
|
|
|
@ The coefficients are stored in |data| row by row where a row are
|
|
coeffs with the same $k$.
|
|
|
|
We first initialize the first row with ones. Then for each other row
|
|
we initialize the first item to one, and other items are a sum of
|
|
coefficients of $n-1$ which is in code |i+j-1|.
|
|
|
|
@<|PascalTriangle| constructor code@>=
|
|
PascalTriangle::PascalTriangle(int n, int k)
|
|
: data(new int[(n+1)*(k+1)]), kmax(k), nmax(n)
|
|
{
|
|
for (int i = 0; i <= n; i++)
|
|
data[i] = 1;
|
|
for (int j = 1; j <= k; j++) {
|
|
data[j*(nmax+1)] = 1;
|
|
for (int i = 1; i <= n; i++)
|
|
data[j*(nmax+1)+i] = noverk(i+j-1,j) + noverk(i+j-1,j-1);
|
|
}
|
|
}
|
|
|
|
@ Clear. Recall, that there are |nmax+1| items in a row.
|
|
@<|PascalTriangle::noverk| code@>=
|
|
int PascalTriangle::noverk(int n, int k) const
|
|
{
|
|
TL_RAISE_IF(k > n || n < 0,
|
|
"Wrong arguments for PascalTriangle::noverk");
|
|
|
|
if (k <= kmax && n-k <= nmax)
|
|
return data[k*(nmax+1)+n-k];
|
|
|
|
if (n-k <= kmax && k <= nmax)
|
|
return data[(n-k)*(nmax+1)+k];
|
|
|
|
TL_RAISE("n or k out of range in PascalTriangle::noverk");
|
|
return 0;
|
|
}
|
|
|
|
@ End of {\tt tl\_static.cpp} file.
|