Memset for distance arrays

[L1nkus]

Calling memset is more efficient and quicker to write, than a loop, to set all values to 0/INF.

What do you think about changing the loops in graph algorithms to memset?

[pllk]

That's a good idea, I'll consider it. In any case, the book should mention the memset function.

[jaens]

GCC will generally convert a zero-initialization loop to a memset, so there's no efficiency difference.

[L1nkus]

Only with -O3, and most judges (for instance codeforces, uva, POI) use -O2, so there's usually an efficiency difference.

[jaens]

You can just put a #pragma GCC optimize ("O3") in your code instead of hand-optimizing it when you do not like the default optimization flags.