offer_16

//面试题16：数值的整数次方
double PowerWithUnsignedExponent(double base,unsigned int exponent)
{
  if(exponent == 0) return 1;
  if(exponent == 1) return base;
  double result=PowerWithUnsignedExponent(base,exponent>>1);
  result*=result;
  if(exponent&0x1==1) result*=base;
  return result;
}