sw/src/pascal/POWER.PS

   1 FUNCTION POWER(X: REAL; Y: INTEGER): REAL ; (*Y >= 0*)
   2 VAR W,Z: REAL; I: INTEGER;
   3 BEGIN W := X; Z := 1; I := Y;
   4     WHILE I > 0 DO
   5     BEGIN (*Z*(W**I) = X ** Y*)
   6        IF ODD(I) THEN Z := Z*W;
   7        I := I DIV 2;
   8        W := SQR(W)
   9     END;
  10     (*Z = X**Y*)
  11     POWER := Z
  12 END;