/*  sifbfact.cpp  by K.Tsuru  */
// function ID 4102  BRADIX
/*******************************************************
SInteger class
It provides the factorial n! using the primitive method.
See BdFact().
********************************************************/
#ifndef SN_H
#include "sn.h"
#endif
SInteger BFact(ulong n){
    long fig = long( (double)Stirling(n)/log10((double)BRADIX) )+1;//the number of figures in BRADIX ver. 2.17
    if(fig >= (long)SNManager::SNMaxSize(SNManager::BIN_INT)){
        SNManager::SetError(SNManager::OUT_OF_RANGE, "BFact", 4102);
    }
    SInteger m((uint)fig, 1);   // m = 1, allocates the memory
    if(n < 2uL) return m;

    ulong i;
    for(i = 2uL; i <= n; i++) IsMult(m, i, m);

    return m;
}