### PaciukZvichainyi's blog

By PaciukZvichainyi, 6 months ago,

What's the reason to name edge like (u, v)? When they are printed letters they seem pretty distinct but with TeX or Latex it's almost impossible to see their difference (especially if you read problem fast). Look, they differ only by one tiny line:

It is really annoying to turn on my brain just to understand this is v or u (or mb v and v, who knows). I think it is especially hard for visually impaired.
Even if there is some "mathematical" idea behind it, just name x and y and all life becomes easier.

Spoiler
• +14

 » 6 months ago, # | ← Rev. 4 →   0 $\,$ The $(u,v)$ naming for the edges, if what I understand is correct, can be explained analogous to how we came to use $m$ and $n$ for input dimensions. First we used $n$ (Stands for "number" or "natural") for a dimension, and then looked for a similar letter for the other dimension, and there was $m$. Same goes for $u$ and $v$. First we used $v$ (Stands for "vertex") for one vertex, and then looked for a similar letter for the other letter, and there was $u$.$\,$ I understand you on that the two letters look too similar, but this has become too much of a common practice anyways. Other common names for variables have their own reasons too, and we can't use them for the sake of clear statements. Say, for example, there is a problem where you are given a planar graph, and therefore the vertices may be placed on a 2-dimensional plane. Now if we name the edges $(x,y)$, will the participants infer that this means one vertex on a plane, or an edge? We don't really know. But to prevent such accidents, we don't want to pull other common names for variables here.$\,$ UPD: $(p,q)$, I think, is one pair of similar alphabets that doesn't serve a very usual purpose. I think we can use this pair instead.$\,$ UPD 2: $(u,v)$ isn't all so bad, we could write them in bold like $\mathbf{(u,v)}$ for example
•  » » 6 months ago, # ^ |   +3 (p, q) usually stands for a fraction
•  » » » 6 months ago, # ^ |   0 (from, to) ? longer but readable.
»
6 months ago, # |
Rev. 4   +4

See here: https://codeforces.com/blog/entry/98347.

Like this:

 I like u and v naming［likes:1,like］ I like u and v naming I would prefer smth different［likes:1,dislike］ I would prefer smth different