square root

When I have some time, I will have a look to this algorithm to calculate the square root of a number:

    int sqrt(int num) {
     int op = num;
     int res = 0;
     int one = 1 << 14; // The second-to-top bit is set: 1L<<30 for long


     // "one" starts at the highest power of four <= the argument.
     while (one > op)
         one >>= 2;

     while (one != 0) {

         if (op >= res + one) {
             op -= res + one;
             res += one << 1;
         }

         res >>= 1;
         one >>= 2;
     }
     return res;
 }

(from Wikipedia)