`fctr_ff'
---------

fctr_ff(POLY)
     :: 1 $BJQ?tB?9`<0$NM-8BBN>e$G$N4{LsJ,2r(B

RETURN
     $B%j%9%H(B

POLY
     $BM-8BBN>e$N(B 1 $BJQ?tB?9`<0(B

   * `fff' $B$GDj5A$5$l$F$$$k(B.

   * $B0lJQ?tB?9`<0$r(B, $B8=:_@_Dj$5$l$F$$$kM-8BBN>e$G4{LsJ,2r$9$k(B.

   * $B7k2L$O(B, [[F1,M1],[F2,M2],...] $B$J$k(B $B%j%9%H$G$"$k(B. $B$3$3$G(B, FI $B$O(B
     monic $B$J4{Ls0x;R(B, MI $B$O$=$N(B $B=EJ#EY$G$"$k(B.

   * POLY $B$N<g78?t$O<N$F$i$l$k(B.

     [178] setmod_ff(2^64-95);
     18446744073709551521
     [179]  fctr_ff(x^5+x+1);
     [[1*x+14123390394564558010,1],[1*x+6782485570826905238,1],
     [1*x+15987612182027639793,1],[1*x^2+1*x+1,1]]

$B;2>H(B
     *Note `setmod_ff': setmod_ff

