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:
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 <vector>
#include <algorithm>
#define MAX 1001
using namespace std;
vector<int> M(MAX,0);
int root(int a)
{
while(M[a]>0) a = M[a];
return a;
}
int Union(int a, int b)
{
int ra = root(a);
int rb = root(b);
if(ra!=rb)
{
M[ra]+=M[rb];
M[rb] = ra;
}
return ra;
}
bool compare(int a, int b){ return a>b?true:false; }
int main()
{
int N;
int k;
int r;
int temp;
vector<int> result;
cin >> N;
for(int i=0; i<N; i++)
{
scanf("%d: ", &k);
cin >> temp;
r = root(temp);
for(int j=1; j<k; j++)
{
cin >> temp;
r = Union(temp,r);
}
M[r]--;
}
for(int i=0; i<1001; i++)
{
if(M[i]<0)
result.push_back(-M[i]);
}
sort(result.begin(),result.end(),compare);
cout << result.size() << endl;
for(int i=0; i<result.size(); i++)
{
if(i!=0)
cout << " ";
cout << result[i];
}
return 0;
}