DJ Delorie wrote:
>> As written, the function will access element [30] of a 30-element array.
> 
> Um, no?

Y-uh-huh!

>       unsigned int mid = low + (high - low) / 2;
> 
> This can never give mid == high unless low == high, which won't happen
> in that loop.
> 
> The math wants to search everything from (including) low to
> (excluding) high.
> 
> (but I'm willing to be proven wrong...)

I am willing to do that!   ;-)

Compile this program, run it under gdb with the input "0xffffffff", and 
step through the code.  You will see it assign the value "30" to "low" 
and use it to access the array.

I suppose you could do it directly just by loading gdb into gdb,
putting a breakpoint at the above function, and then calling it
from gdb with the input 0xffffffff.