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
#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
vector<int> v[1005];
vector<int> hobby[1005];
int N;
bool visit[1005]={false};
vector<int> ans;
void dfs(int curr,int &num)
{
visit[curr]=true;
num++;
for(int i=0;i<v[curr].size();i++)
{
int t=v[curr][i]; //爱好
for(int j=0;j<hobby[t].size();j++) //拥有该爱好的所有人
{
if(!visit[ hobby[t][j] ])
dfs(hobby[t][j],num);
}
}
}
int main(){
scanf("%d",&N);
int num,t;
for(int i=0;i<N;i++)
{
scanf("%d:",&num);
for(int j=0;j<num;j++)
{
scanf("%d",&t);
v[i].push_back(t);
hobby[t].push_back(i);
}
}
for(int i=0;i<N;i++)
if(!visit[i])
{
num=0;
dfs(i,num);
ans.push_back(num);
}
sort(ans.begin(),ans.end());
printf("%d\n",ans.size());
int i=ans.size()-1;
while(i>=0){
printf("%d%c",ans[i],i==0?'\n':' ');
i--;
}
}