PAT A1107. 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<cstdio>#include<iostream>#include<algorithm>using namespace std;const int maxn=10010;int N;int parent[maxn];int member[maxn];int getParent(int a){    while(parent[a]!=a)        a=parent[a];    return a;}//在对成员进行合并时也完成了成员个数的移交 void unions(int a,int b){    int A=getParent(a);    int B=getParent(b);     if(A!=B){        if(A<B) {            parent[B]=A;            member[A]+=member[B];            member[B]=0;        }        else{            parent[A]=B;            member[B]+=member[A];            member[A]=0;        }           }}bool cmp(int a,int b){    return a>b;}int main(void){    freopen("in.txt","r",stdin);    fill(member,member+maxn,0);    cin>>N;    for(int i=1;i<maxn;++i){        parent[i]=i;    }    int n,a,b;    for(int i=0;i<N;++i){        scanf("%d:",&n);        cin>>a;        for(int j=1;j<n;++j){            cin>>b;            unions(a,b);            a=b;        }        int p=getParent(a);        member[p]++;//可以保证人员总共增加N个     }    int cnt=0;    for(int i=0;i<maxn;++i){        if(member[i]!=0)            cnt++;    }    cout<<cnt<<endl;    sort(member,member+maxn,cmp);    for(int i=0;i<cnt;++i){        cout<<member[i];        if(i<cnt-1)            cout<<' ';    }    cout<<endl;    return 0;}