C/C++ Users Group Library 1996 July/C-C++ Users Group Library July 1996.iso/listings/v_12_06/gotwals/sqrt.cpp

Text File | 1994-04-01 | 452b | 16 lines

====================== Listing 7 ======================
/* Compute the greatest integer less than or equal
   to the square root of lint.  From "Factorization
   and Primality Testing", Bressoud
   ------------------------------------------------ */
LargeInt sqrt(const LargeInt& lint) {
   LargeInt a = lint;
   LargeInt b = (lint + one) / two;

   while (b < a) {
      a = b;
      b = (a * a + lint) / (two * a);
   }
   return a;
}