from typing import Callable, Generic, List, TypeVar T = TypeVar("T") class Rerooting(Generic[T]): __slots__ = ("adjList", "_n", "_decrement") def __init__(self, n: int, decrement: int = 0): self.adjList = [[] for _ in range(n)] self._n = n self._decrement = decrement def addEdge(self, u: int, v: int) -> None: u -= self._decrement v -= self._decrement self.adjList[u].append(v) self.adjList[v].append(u) def rerooting( self, e: Callable[[int], T], op: Callable[[T, T], T], composition: Callable[[T, int, int, int], T], root=0, ) -> List["T"]: root -= self._decrement assert 0 <= root < self._n parents = [-1] * self._n order = [root] stack = [root] while stack: cur = stack.pop() for next in self.adjList[cur]: if next == parents[cur]: continue parents[next] = cur order.append(next) stack.append(next) dp1 = [e(i) for i in range(self._n)] dp2 = [e(i) for i in range(self._n)] for cur in order[::-1]: res = e(cur) for next in self.adjList[cur]: if parents[cur] == next: continue dp2[next] = res res = op(res, composition(dp1[next], cur, next, 0)) res = e(cur) for next in self.adjList[cur][::-1]: if parents[cur] == next: continue dp2[next] = op(res, dp2[next]) res = op(res, composition(dp1[next], cur, next, 0)) dp1[cur] = res for newRoot in order[1:]: parent = parents[newRoot] dp2[newRoot] = composition(op(dp2[newRoot], dp2[parent]), parent, newRoot, 1) dp1[newRoot] = op(dp1[newRoot], dp2[newRoot]) return dp1 import sys input = lambda: sys.stdin.readline().rstrip("\r\n") from typing import Tuple INF = int(4e18) MOD = 998244353 pow10 = [1] for _ in range(100): pow10.append(pow10[-1] * 10 % MOD) if __name__ == "__main__": n = int(input()) nums = [int(x) for x in input().split()] edges = [] for _ in range(n - 1): u, v = map(int, input().split()) u, v = u - 1, v - 1 edges.append((u, v)) pows = [pow10[len(str(nums[i]))] for i in range(n)] E = Tuple[int, int] # (count,sum) 节点个数,路径和 def e(root: int) -> E: return (0, 0) def op(childRes1: E, childRes2: E) -> E: c = childRes1[0] + childRes2[0] s = childRes1[1] + childRes2[1] if s >= MOD: s -= MOD return (c, s) def composition(fromRes: E, parent: int, child: int, direction: int) -> E: """direction: 0: child -> parent, 1: parent -> child""" c, s = fromRes from_ = child if direction == 0 else parent v, p = nums[from_], pows[from_] return (c + 1, (s * p + v * (c + 1)) % MOD) R = Rerooting(n) for u, v in edges: R.addEdge(u, v) dp = R.rerooting(e, op, composition) # !注意dp不包含根节点 res = 0 for i in range(n): c, s = dp[i] v, p = nums[i], pows[i] res += s * p + v * (c + 1) res %= MOD print(res % MOD)