program without using mathamatical operators

[sekhar_ps]

how would you print 2 powers series from 0 to 100 (like pow(2,0),pow(2,1).........pow(2,100)) with out using mathematical operators

[Banfa]

I wouldn't seems like a pointless exersise to me, however if you must then you need to specifiy exactly which operators and forbidden. What you the bitwise operators?

[sekhar_ps]

hi,
thanx for the reply,what iam saying is with out using mathematical operators not bitwise operators.

[D_C]

One problem you may run into is overflow. In this example, it prints 2^29, but not 2^30. Integers are 32-bit numbers, the most significant is reserved for the sign. If we include 2^30 in the loop, we shift it, 2^31 becomes a negative number, and the loop is still valid. One could always test while(number != (1<<31)). However, if the loop keeps going, since integers are typically 32-bit, (1 << 32) = 0 because the 1 overflows and is lost.

int main()
{
  int number = 1; // assume 32-bit.
  while(number != (1 << 31)) // logical shift left, bitwise operator
  {
    cout << number << endl;
    number = (number << 1);
  }
      system("PAUSE");
      return 0;
}

[Banfa]

You should be careful using signed values in shift operations, particularly the right shift operation on a signed value is either undefined behaviour or implementation defined behaviour.

I normally try to stick to unsigned variables when using shift operators as the results are more consistent cross platform.

If you are using unsigned values you can then use 0 as the end condition of the loop

int main()
{
    unsigned int number; // assume 32-bit.
 
    for(number=1; number != 0; number <<= 1)
    {
        cout << number << endl;
    }
    system("PAUSE");
    return 0;
}

Unfortunately this doesn't get you to the 100th power and the shift operators do not work on floating point types.