Codeforces Round 309 (Div. 1)
D
Nudist Beach
Codeforces
2300
原题
← CE →
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Nudist Beach is planning a military operation to attack the Life Fibers. In this operation, they will attack and capture several cities which are currently under the control of the Life Fibers.

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There are $*n*$ cities, labeled from 1 to $*n*$, and $*m*$ bidirectional roads between them. Currently, there are Life Fibers in every city. In addition, there are $*k*$ cities that are fortresses of the Life Fibers that cannot be captured under any circumstances. So, the Nudist Beach can capture an arbitrary non-empty subset of cities with no fortresses.

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After the operation, Nudist Beach will have to defend the captured cities from counterattack. If they capture a city and it is connected to many Life Fiber controlled cities, it will be easily defeated. So, Nudist Beach would like to capture a set of cities such that for each captured city the ratio of Nudist Beach controlled neighbors among all neighbors of that city is as high as possible.

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More formally, they would like to capture a non-empty set of cities $*S*$ with no fortresses of Life Fibers. The strength of a city image is defined as (number of neighbors of $*x*$ in $*S*$) / (total number of neighbors of $*x*$). Here, two cities are called neighbors if they are connnected with a road. The goal is to maximize the strength of the weakest city in $*S*$.

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Given a description of the graph, and the cities with fortresses, find a non-empty subset that maximizes the strength of the weakest city.

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Input

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The first line of input contains three integers $*n*, *m*, *k*$ ($2  ≤  *n*  ≤ 100 000$, $1 ≤ *m* ≤ 100 000$, $1 ≤ *k* ≤ *n* - 1$).

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The second line of input contains $*k*$ integers, representing the cities with fortresses. These cities will all be distinct.

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The next $*m*$ lines contain the roads. The $*i*$-th of these lines will have 2 integers $*a*_{*i*}, *b*_{*i*}$ ($1 ≤ *a*_{*i*}, *b*_{*i*} ≤ *n*$, $*a*_{*i*} ≠ *b*_{*i*}$). Every city will have at least one road adjacent to it.

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There is no more than one road between each pair of the cities.

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Output

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The first line should contain an integer $*r*$, denoting the size of an optimum set ($1 ≤ *r* ≤ *n* - *k*$).

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The second line should contain $*r*$ integers, denoting the cities in the set. Cities may follow in an arbitrary order. This line should not contain any of the cities with fortresses.

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If there are multiple possible answers, print any of them.

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Note

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The first example case achieves a strength of 1/2. No other subset is strictly better.

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The second example case achieves a strength of 1. Note that the subset doesn't necessarily have to be connected.

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样例

Input #1
9 8 4
3 9 6 8
1 2
1 3
1 4
1 5
2 6
2 7
2 8
2 9
Output #1
3
1 4 5
InputCopy OutputCopy
Input #2
10 8 2
2 9
1 3
2 9
4 5
5 6
6 7
7 8
8 10
10 4
Output #2
8
1 5 4 8 10 6 3 7
InputCopy OutputCopy
题目信息
题号
553D
时间限制
2 s
内存限制
256 MB
标签
二分
图论
贪心

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。