Exemple #1
0
        /* reduces this DBIG mod a BIG, and returns the BIG */
        public virtual BIG Mod(BIG c)
        {
            int k = 0;

            Norm();
            DBIG m = new DBIG(c);
            DBIG r = new DBIG(0);

            if (Comp(this, m) < 0)
            {
                return(new BIG(this));
            }

            do
            {
                m.Shl(1);
                k++;
            } while (Comp(this, m) >= 0);

            while (k > 0)
            {
                m.Shr(1);

                r.Copy(this);
                r.Sub(m);
                r.Norm();
                CMove(r, (int)(1 - ((r.w[BIG.DNLEN - 1] >> (BIG.CHUNK - 1)) & 1)));

                k--;
            }
            return(new BIG(this));
        }
Exemple #2
0
        /* return this/c */
        public virtual BIG Div(BIG c)
        {
            int  d, k = 0;
            DBIG m  = new DBIG(c);
            DBIG dr = new DBIG(0);
            BIG  r  = new BIG(0);
            BIG  a  = new BIG(0);
            BIG  e  = new BIG(1);

            Norm();

            while (Comp(this, m) >= 0)
            {
                e.FShl(1);
                m.Shl(1);
                k++;
            }

            while (k > 0)
            {
                m.Shr(1);
                e.Shr(1);

                dr.Copy(this);
                dr.Sub(m);
                dr.Norm();
                d = (int)(1 - ((dr.w[BIG.DNLEN - 1] >> (BIG.CHUNK - 1)) & 1));
                CMove(dr, d);
                r.Copy(a);
                r.Add(e);
                r.Norm();
                a.CMove(r, d);
                k--;
            }
            return(a);
        }