tpzpermutation.cpp

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#include "tpzpermutation.h"
#include "TPZStream.h"
#include "Hash/TPZHash.h"

TPZPermutation::TPZPermutation(int n) : fCounter(n,0), fOrder(n,-1)
{
                int i;
                for(i=0; i<n; i++) fOrder[i] = i;
}

TPZPermutation::TPZPermutation(const TPZPermutation &copy) : fCounter(copy.fCounter), fOrder(copy.fOrder)
{
}

TPZPermutation &TPZPermutation::operator=(const TPZPermutation &copy)
{
                fCounter = copy.fCounter;
                fOrder = copy.fOrder;
                return *this;
}

TPZPermutation::~TPZPermutation()
{
}

void TPZPermutation::Permute(const TPZVec<int> &in, TPZVec<int> &out) const
{
                int i,n=fCounter.NElements();
                for(i=0; i<n; i++) out[fOrder[i]] = in[i];
}
void TPZPermutation::Permute(const TPZVec<int64_t> &in, TPZVec<int64_t> &out) const
{
                int i,n=fCounter.NElements();
                for(i=0; i<n; i++) out[fOrder[i]] = in[i];
}

void TPZPermutation::operator++()
{
                int n = fCounter.NElements();
                int i = n-2;
                while(i >= 0 && ((++fCounter[i]) %= n-i) == 0) i--;
                fOrder.Fill(-1);
                int count;
                for(i=0; i<n; i++)
                {
                                count = 0;
                                int index = 0;
                                while(fCounter[i] > count || fOrder[index] != -1)
                                {
                                                if(fOrder[index] == -1) count++;
                                                index++;
                                }
                                fOrder[index] = i;
                }
}

bool TPZPermutation::IsFirst()
{
                int nel = fCounter.NElements();
                int in;
                for(in=0; in<nel; in++) if(fCounter[in] != 0) return false;
                return true;
}

int TPZPermutation::ClassId() const {
    return Hash("TPZPermutation");
}

void TPZPermutation::Read(TPZStream& buf, void* context) {
    buf.Read(fCounter);
    buf.Read(fOrder);
}

void TPZPermutation::Write(TPZStream& buf, int withclassid) const {
    buf.Write(fCounter);
    buf.Write(fOrder);
}