PAT 1107. Social Clusters (30)

1107. Social Clusters (30)

时间限制

1000 ms

内存限制

65536 kB

代码长度限制

16000 B

判题程序

Standard

作者

CHEN, Yue

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:

K_i: h_i[1] h_i[2] ... h_i[K_i]

where K_i (>0) is the number of hobbies, and h_i[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:

83: 2 7 101: 42: 5 31: 41: 31: 44: 6 8 1 51: 4

Sample Output:

34 3 1

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又是一道Union-Find题目，代码如下：

#include <iostream>#include <algorithm>#include <cmath>#include <map>#include <set>#include <vector>using namespace std;int N;int cluster[1001]={0};int findRoot(int x){if(cluster[x] == x)return x;// cout<<"***"<<endl;int rx = cluster[x];while(cluster[rx]!=rx){int rrx = findRoot(rx);rx = rrx;}cluster[x] = rx;return rx;}void Union(int a, int b){int ra = findRoot(a);int rb = findRoot(b);cluster[rb] = ra;}int main(void){cin>>N;vector<int> hobbies;vector<int> person(N);for(int i = 1; i <= N; i++){int number;cin>>number;getchar();hobbies.clear();hobbies.resize(number);for(int j = 0; j < number; j++){cin>>hobbies[j];if(cluster[hobbies[j]] <= 0)cluster[hobbies[j]] = hobbies[j];}if(hobbies.size() > 1){for(int j = 1; j < hobbies.size(); j++){Union(hobbies[0],hobbies[j]);}}person[i-1] = findRoot(hobbies[0]);}set<int> count;for(int i = 1; i <= 1000; i++){if(cluster[i] <= 0)continue;int tmp = findRoot(cluster[i]);count.insert(tmp);}vector<int> result(1001,0);for(int i = 0; i < N; i++){person[i] = findRoot(person[i]);result[person[i]]++;}cout<<count.size()<<endl;sort(result.begin(),result.end(),greater<int>());for(int i = 0; i <= 1001; i++){if(result[i] <= 0)break;if(i)cout<<" "<<result[i];elsecout<<result[i];}return 0;}