programming puzzlesWrite a "Hello World" program in 'C' without using a semicolon. (this is tricky) C/C++ : Exchange two numbers without using a temporary variable. (somehow classic way) C/C++ : Find if the given number is a power of 2. (somehow classic way) Write a program whose printed output is an exact copy of the source. Needless to say, merely echoing the actual source file is not allowed. (a bit hard to think) source: http://developers.slashdot.org/article.pl?sid=04/12/04/0116231

interesting... let me try 1&2...1. #include void main() { if (printf("hello world\n")) {} } 2. a=a+b; b=a-b; a=a-b;

(3) can be done by less than 5 instructionsBy classic (or classical?), I mean a lot of people use the method.

can be simpler and faster