Nebius Welcome Round (Div. 1 + Div. 2)
F
Approximate Diameter
Codeforces
2700
原题
← EG →
翻译中…

Jack has a graph of $n$ vertices and $m$ edges. All edges are bidirectional and of unit length. The graph is connected, i. e. there exists a path between any two of its vertices. There can be more than one edge connecting the same pair of vertices. The graph can contain self-loops, i. e. edges connecting a node to itself.

翻译中…

The distance between vertices $u$ and $v$ is denoted as $\rho(u, v)$ and equals the minimum possible number of edges on a path between $u$ and $v$. The diameter of graph $G$ is defined as the maximum possible distance between some pair of its vertices. We denote it as $d(G)$. In other words, $$d(G) = \max_{1 \le u, v \le n}{\rho(u, v)}.$$

翻译中…

Jack plans to consecutively apply $q$ updates to his graph. Each update adds exactly one edge to the graph. Denote as $G_i$ the graph after exactly $i$ updates are made. Jack wants to calculate $q + 1$ values $d(G_0), d(G_1), d(G_2), \ldots, d(G_q)$.

翻译中…

However, Jack suspects that finding the exact diameters of $q + 1$ graphs might be a difficult task, so he is fine with approximate answers that differ from the correct answers no more than twice. Formally, Jack wants to find a sequence of positive integers $a_0, a_1, a_2, \ldots, a_q$ such that $$\left\lceil \frac{d(G_i)}{2} \right\rceil \le a_i \le 2 \cdot d(G_i)$$ for each $i$.

翻译中…

Hacks

翻译中…

You cannot make hacks in this problem.

翻译中…

Input

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The first line of the input contains three integers $n$, $m$, and $q$ ($2 \leq n \leq 10^5$, $n - 1 \leq m \leq 10^5$, $0 \leq q \leq 10^5$), the number of vertices in the given graph, the number of edges and the number of updates, respectively.

翻译中…

Then follow $m$ lines describing the initial edges of the graph. The $i$-th of these lines contains two integers $u_i$ and $v_i$ ($1 \leq u_i, v_i \leq n$), the indexes of the vertices connected by the $i$-th edge.

翻译中…

Then follow $q$ lines describing the updates. The $i$-th of these lines contains two integers $u'_i$ and $v'_i$ ($1 \leq u'_i, v'_i \leq n$), the indexes of the vertices connected by the edge that is added to the graph in the $i$-th update.

翻译中…

Important note. For testing purposes, the input data may contain some extra lines after the mentioned input format. These will be used by the checker to verify your answer. They are not a part of the test data, you should not use them in any way and you can even omit reading them.

翻译中…

Output

翻译中…

Print a sequence of $q + 1$ positive integers $a_0, a_1, a_2, \ldots, a_q$. The $i$-th of these integers should differ from the diameter of graph $G_i$ no more than twice.

翻译中…

Note

翻译中…

In the first example, the correct sequence of $d(G_0), d(G_1), d(G_2), \ldots, d(G_q)$ is $6, 6, 6, 3, 3, 3, 2, 2, 2$.

翻译中…

In the second example, the input contains an extra line that you can omit reading. It is not a part of the test and will be used for verifying your answer. The output of the second example contains the correct values of $d(G_i)$.

翻译中…

样例

Input #1
9 10 8
1 2
2 3
2 4
3 5
4 5
5 6
5 7
6 8
7 8
8 9
3 4
6 7
2 8
1 9
1 6
4 9
3 9
7 1
Output #1
10 6 5 6 2 4 2 2 1
InputCopy OutputCopy
Input #2
8 7 9
1 2
2 3
3 4
4 5
5 6
6 7
7 8
1 5
3 7
2 4
4 6
6 8
8 2
5 4
2 4
3 3
1 652997 124613 653029 653029 124613 124613 124613 648901 124613 653029
Output #2
7 5 4 4 4 3 3 3 3 3
InputCopy OutputCopy
题目信息
题号
1804F
时间限制
2 s
内存限制
512 MB
标签
二分
分治
图论
最短路

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。