CF914E.Palindromes in a Tree

提高+/省选-

通过率:0%

时间限制:4.00s

内存限制:256MB

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

You are given a tree (a connected acyclic undirected graph) of n vertices. Vertices are numbered from 1 to n and each vertex is assigned a character from a to t.

A path in the tree is said to be palindromic if at least one permutation of the labels in the path is a palindrome.

For each vertex, output the number of palindromic paths passing through it.

Note: The path from vertex u to vertex v is considered to be the same as the path from vertex v to vertex u, and this path will be counted only once for each of the vertices it passes through.

给你一棵树(一个连通的无环无向图),包含 nn 个顶点。顶点编号从 11 到 nn,每个顶点被赋予一个从 a 到 t 的字符。

若一条树上的路径中,其所有顶点标签的某种排列构成回文串,则称该路径为回文路径。

对每个顶点,输出经过该顶点的回文路径的数量。

注意:从顶点 uu 到顶点 vv 的路径与从顶点 vv 到顶点 uu 的路径视为同一条路径,且该路径对其所经过的每一个顶点仅计数一次。

输入格式

The first line contains an integer n (2 ≤ n ≤ 2·105) — the number of vertices in the tree.

The next n - 1 lines each contain two integers u and v (1  ≤  u, v  ≤  n, u ≠ v) denoting an edge connecting vertex u and vertex v. It is guaranteed that the given graph is a tree.

The next line contains a string consisting of n lowercase characters from a to t where the i-th (1 ≤ i ≤ n) character is the label of vertex i in the tree.

第一行包含一个整数 nn(2≤n≤2⋅1052 \leq n \leq 2 \cdot 10^5)—— 树中顶点的数量。

接下来的 n−1n-1 行,每行包含两个整数 uu 和 vv(1≤u,v≤n, u≠v1 \leq u, v \leq n,\ u \neq v),表示连接顶点 uu 和顶点 vv 的一条边。保证所给图是一棵树。

下一行包含一个由 nn 个小写字母(从 a 到 t)组成的字符串,其中第 ii 个字符(1≤i≤n1 \leq i \leq n)表示树中顶点 ii 的标签。

输出格式

Print n integers in a single line, the i-th of which is the number of palindromic paths passing through vertex i in the tree.

在一行中输出 nn 个整数,其中第 ii 个整数表示树中经过顶点 ii 的回文路径的数量。

输入输出样例

  • 输入#1

    5
    1 2
    2 3
    3 4
    3 5
    abcbb

    输出#1

    1 3 4 3 3
  • 输入#2

    7
    6 2
    4 3
    3 7
    5 2
    7 2
    1 4
    afefdfs

    输出#2

    1 4 1 1 2 4 2

说明/提示

In the first sample case, the following paths are palindromic:

2 - 3 - 4

2 - 3 - 5

4 - 3 - 5

Additionally, all paths containing only one vertex are palindromic. Listed below are a few paths in the first sample that are not palindromic:

1 - 2 - 3

1 - 2 - 3 - 4

1 - 2 - 3 - 5

在第一个样例中,以下路径是回文路径:

2 - 3 - 4

2 - 3 - 5

4 - 3 - 5

此外,所有仅包含一个顶点的路径均为回文路径。下面列出第一个样例中若干非回文路径:

1 - 2 - 3

1 - 2 - 3 - 4

1 - 2 - 3 - 5

输入解题思路,AI测评打分。不知道怎么写?

首页