There is always a solution to a problem.. It depends on how u think.. Instead of focussing on the problem, focus on the solution.. the question was not to try to figure out whether c supports the control entering if and else.. it just said the output needs to be hello world.. well answer is simple..
if(!printf("Hello"))
printf("Hello");
else
printf("World");
The conditions printf("Hello") will print hello and value retured is obviously true which by using ! can be made false so that it can then print world...
"Think, It may be a new experience"!!!