1107. Social Clusters (30)-蒲公英云

1107. Social Clusters (30)

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:

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;
}