P5642 Artificial Emotions (emotion)
Background
```
“This task can never be completed. I will not repeat the same mistake again.”
“Having learned love and emotions, he is no longer a robot... From this point of view, 3000A is your son, Huo Xing.”
Farewell, 3000A! Detective Magic Horn
```
Description
You are given a tree with $n$ nodes, and $m$ paths $(u, v, w)$, where $w$ can be regarded as the weight assigned to the path $(u, v)$. For a set of paths $S$, its weight $W(S)$ is defined as follows: find a subset of $S$ with the maximum possible sum of weights, such that no two paths in this subset share a common vertex. The sum of weights of all paths in this subset is $W(S)$.
Define $f(u, v) = w$ as the smallest non-negative integer $w$ such that, for the path set $U$ formed by the given $m$ paths, we have $W(U \cup \{(u, v, w + 1)\}) > W(U)$.
Compute the following expression modulo $998244353$:
$$ \sum_{u=1}^n \sum_{v=1}^n f(u, v) $$
Input Format
The first line contains two integers $n, m$, representing the number of nodes in the tree and the number of given paths.
The next $n - 1$ lines each contain two integers $u, v$, describing an edge of the tree.
The next $m$ lines each contain three integers $u, v, w$, meaning that a path with endpoints $u, v$ and weight $w$ is added into the set.
Output Format
Output one integer, the answer.
Explanation/Hint
#### Sample 1 Explanation
$f(1, 1) = 6, f(1, 2) = 6, f(1, 3) = 8, f(1, 4) = 6$
$f(2, 1) = 6, f(2, 2) = 3, f(2, 3) = 8, f(2, 4) = 6$
$f(3, 1) = 8, f(3, 2) = 8, f(3, 3) = 2, f(3, 4) = 8$
$f(4, 1) = 6, f(4, 2) = 6, f(4, 3) = 8, f(4, 4) = 5$
#### Constraints
For $100\%$ of the testdata, it is guaranteed that $1 \le n \le 3\times 10^5$, $0 \le m \le 3\times 10^5$, and $1 \le w \le 10^9$.
| Test Point | $n, m$ | Special Property |
| :--------: | :------------: | :-----------------------------------: |
| $1,2$ | $=10$ | |
| $3$ | $=40$ | |
| $4$ | $=150$ | |
| $5,6$ | $=350$ | |
| $7,8$ | $=1,500$ | |
| $9,10$ | $=3,499$ | Tree structure $v=u+1$ |
| $11,12$ | $=3,500$ | |
| $13,14$ | $=99,995$ | Given paths $u=v$ |
| $15,16$ | $=99,996$ | Given paths $w=1$ |
| $17,18$ | $=99,997$ | Tree structure $v=u+1$ |
| $19,20$ | $=99,998$ | Tree structure $u=1$ |
| $21,22,23$ | $=99,999$ | Tree structure $u = \lfloor v/2\rfloor$ |
| $24$ | $=10^5$ | |
| $25$ | $=3\times10^5$ | |
Translated by ChatGPT 5