# verification-helper: PROBLEM https://atcoder.jp/contests/abc221/tasks/abc221_f
import sequtils, math
import cplib/graph/graph
import cplib/tree/diameter
import cplib/modint/modint
proc scanf(formatstr: cstring){.header: "<stdio.h>", varargs.}
proc ii(): int {.inline.} = scanf("%lld\n", addr result)
type mint = modint998244353_montgomery
var n = ii()
var g = initUnWeightedUnDirectedStaticGraph(n)
for i in 0..<n-1:
var u, v = ii() - 1
g.add_edge(u, v)
g.build
var (d, path) = g.diameter_path
if d mod 2 == 0:
var center = path[d div 2]
var cnt = 0
proc find_leaf(x, par, di: int) =
if di == d div 2 - 1: cnt += 1
for y in g[x]:
if y == par: continue
find_leaf(y, x, di+1)
var t = newSeq[mint]()
for x in g[center]:
cnt = 0
find_leaf(x, center, 0)
t.add(mint(cnt + 1))
echo (t.foldl(a * b) - t.sum + t.len - 1)
else:
var c1 = path[d div 2]
var c2 = path[(d+1) div 2]
proc find_leaf(x, par, di: int): int =
if di == d div 2: result += 1
for y in g[x]:
if y == par: continue
result += find_leaf(y, x, di+1)
var ch1 = find_leaf(c1, c2, 0)
var ch2 = find_leaf(c2, c1, 0)
echo (mint(ch1) * mint(ch2))
Traceback (most recent call last):
File "/home/runner/.local/lib/python3.12/site-packages/onlinejudge_verify/documentation/build.py", line 71, in _render_source_code_stat
bundled_code = language.bundle(stat.path, basedir=basedir, options={'include_paths': [basedir]}).decode()
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/runner/.local/lib/python3.12/site-packages/onlinejudge_verify/languages/nim.py", line 86, in bundle
raise NotImplementedError
NotImplementedError
verify/tree/diameter_path_static_test_.nim
cplib/graph/graph.nim