/*  sffbntbl.cpp  by K.Tsuru  */
// function ID 7101     DRADIX
/************************************************
SFraction class
It provodes the table of Bernoulli's numbers B[n].
*************************************************/
#ifndef SN_H
#include "sn.h"
#endif

void BernNumTable(SNBlock <SFraction>& Bn, uint N){
    SNBlock <SInteger> t(2u*N+1);
    Bn.reserve(N);
    int err = (t.Error() != t.NORMAL) || (Bn.Error() != Bn.NORMAL);
    if(err) t[0].SetError(t[0].OUT_OF_RANGE,"BernNumTable", 7101);

    uint i, n;
    SInteger q, b1, b2, d;
    SLong B1, B2;


    for(i = 0; i <= 2*N; i++) t[i].SetZero();
    q = 1;  t[1] = 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){
            IsMult(q, 4, q);        // q *= 4;
            IsSub(q, 1, d);
            b2 = q*d;               // b2 = q*(q-1);
            IsMult(t[0], n, b1);
            B1 = b1.ConvToDec();
            B2 = b2.ConvToDec();    // radix conversion
            Bn[n/2].Set(B1, B2);
            Bn[n/2].Reduce();
        }
    }
}