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Colorful Tree Again

2000ms 524288K

Description:

An edge-weighted tree of $$$n$$$ nodes is given with each edge colored in some color. Each node of this tree can be blocked or unblocked, all nodes are unblocked initially.

A simple path is a path in a graph that does not have repeating nodes. The length of a path is defined as the sum of weights of all edges on the path.

A path is good when it is a simple path consisting of edges of the same color $$$c$$$, all edges of color $$$c$$$ are on this path, and every node on the path is unblocked.

You need to operate $$$2$$$ kinds of queries:

  1. block a node,
  2. unblock a node.

After each query, print the maximum length among all good paths. If there are no good paths, print $$$0$$$.

Input:

The first line contains two integers $$$n$$$, $$$q$$$ ($$$1 \leq n,q \leq 2\cdot 10^5$$$) — the number of nodes and the number of queries.

Then $$$n-1$$$ lines follow, each containing four integers $$$u$$$, $$$v$$$, $$$w$$$ and $$$c$$$ ($$$1 \leq u,v,w,c \leq n$$$; $$$u \not = v$$$), denoting a weighted edge connecting node $$$u$$$ and node $$$v$$$ with weight $$$w$$$ and color $$$c$$$. It is guaranteed that these edges form a tree.

Then $$$q$$$ lines follow, each containing two integers $$$p$$$ and $$$x$$$ ($$$p = 0$$$ or $$$p = 1$$$, $$$1\leq x\leq n$$$), denoting a query:

  1. if $$$p = 0$$$, block the node $$$x$$$. It's guaranteed that it's not blocked at this time;
  2. if $$$p = 1$$$, unblock the node $$$x$$$. It's guaranteed that it's blocked at this time.

Output:

For each query, print the maximum length of a good path. If there are no good paths, print $$$0$$$.

Sample Input:

5 4
4 1 3 4
5 2 4 4
3 1 3 2
1 2 5 1
0 4
0 3
0 2
1 3

Sample Output:

5
5
0
3

Sample Input:

5 5
4 1 4 4
4 5 2 2
3 1 2 4
3 2 3 1
0 3
0 4
1 3
1 4
0 1

Sample Output:

2
0
3
6
3

Sample Input:

6 9
3 2 2 3
2 4 4 2
3 1 5 5
6 4 3 2
5 3 1 3
0 2
0 4
0 5
0 6
1 2
1 4
1 5
0 3
1 6

Sample Output:

5
5
5
5
5
5
5
0
7

Sample Input:

1 2
0 1
1 1

Sample Output:

0
0

Informação

Codeforces

Provedor Codeforces

Código CF1787G

Tags

brute forcedata structurestrees

Submetido 0

BOUA! 0

Taxa de BOUA's 0%

Datas 09/05/2023 10:36:28

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