\(\def \set #1#2{\{ #1 \ \vert \ #2 \}}\) \(\def \order #1{\lvert {#1} \rvert}\) 問題概要 \(N\) 頂点の tree \(G\) が与えられる． \begin{align} U &:= \set{(i,j,k) \in V(G)}{ i,j,k \text{は相異なる} }, \\ L &:= \set{(i,j,k) \in U}{i,j,k \tex…

\(\def \set #1#2{\{ #1 \ \vert \ #2 \}}\) ABC314F 問題概要 有向 tree \(T\) を構成する． \(N := \{0, 1, \cdots, N-1\}\) \(|V(T)| = 2N-1\) The set \(L := \set{\{i\}}{ i \in N}\) is the set of leafs of T. For any vertex \(x\) of \(V\) is a su…