What's wrong with this code? (Or: ALWAYS compile with -Wall.)

[Yoni]

Here is some code I wrote today for practice.
This code has a terrible, evil bug that causes it to seg-fault.
Can you spot the bug?

(Note: Compiling it = cheating. Compilation with -Wall reveals the answer.)

Code Select Expand


... irrelevant code snipped ...

bool HeapEmpty()
{
return HeapSize == 0;
}

void HandleGroup(uint i)
{
// Is the heap empty?
if (HeapEmpty()) {
// Nothing to do with this group =\
return;
}

// Get the currently valid trip that has the least chance of attracting more groups.
uint TIdx = HeapExtractMin();

// Match!
NumMatched++;
Match[Arr[i].Index + 1] = TIdx + 1;
}

... irrelevant code snipped ...


[Mangix]

either the uint thing or something else .

[Newby]

It's never going to return, even if the heap is empty.

Change "=\" to "=/" is my best guess. It seems you commented out return on accident.

The only reason I know this is because I have done the same thing (though it would seem that my mistake (forgetting to add to a number) is less severe than yours). Yay for syntax highlighting! I've never coded in pico since. vim for life.

[Yoni]

Newby rocks.

Actually, it might return, just not from the "return;" line.
But, as soon as we hit HeapExtractMin(), it tries to extract from an empty heap, which sometimes crashes and otherwise returns junk.

[Newby]

Newby rocks.

Actually, it might return, just not from the "return;" line.
But, as soon as we hit HeapExtractMin(), it tries to extract from an empty heap, which sometimes crashes and otherwise returns junk.

Yeah, I guess I should have specified that it won't return from that return line if no heap exists.

That's also a reason why I use /* code blocks */

[Yoni]

[Warrior]

Why do you talk like this?

[R.a.B.B.i.T]

Cause they want to look cool

[Yoni]

It's a spoiler blocker. If you don't want to see the answer you don't have to.

[Soul Taker]

I think they're using a different theme, since not all themes have black quotes.