/*  slftctbl.cpp  by K.Tsuru  */ 
// function ID 4105 DRADIX
/**********************************************
SLong class
It makes a table of tangent coefficients T[n]
using the arithmetic of SInteger class.
T[0] = 0, T[n] = Tn (n>0)
**********************************************/
#ifndef SN_H
#include "sn.h"
#endif

void TanCoeffTable(SNBlock <SLong>& T, uint N){
    SNBlock <SInteger> t(2*N+1);
    T.reserve(N);

    int err = (t.Error() != t.NORMAL) || (T.Error() != T.NORMAL);
    if(err) t[0].SetError(t[0].OUT_OF_RANGE,"TanCoeffTable", 7101);
    uint i, n;

    T[0].SetZero();
    for(i = 0; i <= 2*N; i++) t[i].SetZero();
    t[1].SetLong(1);
    for(n = 2; n <= 2*N; n++){
        for(i = 1; i< n; i++)  IsMult(t[i], i, t[i-1]);
        t[n-1].SetZero();
        for(i = n; i >= 2; i--) IIAdd(t[i], t[i-2], t[i]);
        if(n % 2 == 0) T[n/2] = t[0].ConvToDec();   // radix conversion
    }
}