1107. Social Clusters (30)

迈不过友情╰ 2022-05-30 07:19 107阅读 0赞

When register on a social network, you are always asked to specify your hobbies in order to find some potential friends with the same hobbies. A "social cluster" is a set of people who have some of their hobbies in common. You are supposed to find all the clusters.

**Input Specification:**

Each input file contains one test case. For each test case, the first line contains a positive integer N (<=1000), the total number of people in a social network. Hence the people are numbered from 1 to N. Then N lines follow, each gives the hobby list of a person in the format:

Ki: hi\[1\] hi\[2\] ... hi\[Ki\]

where Ki (>0) is the number of hobbies, and hi\[j\] is the index of the j-th hobby, which is an integer in \[1, 1000\].

**Output Specification:**

For each case, print in one line the total number of clusters in the network. Then in the second line, print the numbers of people in the clusters in non-increasing order. The numbers must be separated by exactly one space, and there must be no extra space at the end of the line.

**Sample Input:**

8
    3: 2 7 10
    1: 4
    2: 5 3
    1: 4
    1: 3
    1: 4
    4: 6 8 1 5
    1: 4

**Sample Output:**

3
    4 3 1

--------------------

题目大意：

代码：

#include<stdio.h>
    #include<algorithm>
    using namespace std;
    int farther[1010],hobby[1010],clusters[1010];
    bool cmp(int a,int b)
    {
    	return a>b;
    }
    int find(int x)
    {
    	while(x!=farther[x])
    	{
    		x=farther[x];
    	}
    	return x;
    }
    void Union(int a,int b)
    {
    	int findA=find(a);
    	int findB=find(b);
    	if(findA!=findB)
    	{
    		farther[findA]=findB;
    	}
    }
    int main()
    {
    	int i,j,n,m,k,t,cnt;
    	scanf("%d",&n);
    	for(i=1;i<=n;i++)
    	{
    		farther[i]=i;
    	}
    	for(i=1;i<=n;i++)
    	{
    		scanf("%d:",&m);
    		for(j=0;j<m;j++)
    		{
    			scanf("%d",&k);
    			if(hobby[k]==0)
    			{
    				hobby[k]=i;
    			}
    			Union(i,find(hobby[k]));
    		}
    	}
    	for(i=1;i<=n;i++)
    	{
    		clusters[find(i)]++;
    	}
    	cnt=0;
    	for(i=1;i<=n;i++)
    	{
    		if(clusters[i]!=0)
    		{
    			cnt++;
    		}
    	}
    	printf("%d\n",cnt);
    	sort(clusters,clusters+n+1,cmp);
    	for(i=0;i<cnt;i++)
    	{
    		if(i==0)
    		{
    			printf("%d",clusters[i]);
    		}
    		else
    		{
    			printf(" %d",clusters[i]);
    		}
    	}
    	printf("\n");
    	return 0;
    }