1107 Social Clusters 30 ☆☆★
github地址：https://github.com/iofu728/PAT-A-by-iofu728
难度：☆☆★
关键词：合并 并查集
题目
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 integerN(≤1000), the total number of people in a social network. Hence the people are numbered from 1 toN. ThenNlines follow, each gives the hobby list of a person in the format:
Ki: hi[1] hi[2] ... hi[Ki]
whereKi(>0) is the number of hobbies, andhi[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
大意
每个人都有一堆兴趣，只要一堆人中存在两个人之间兴趣有重合，记为一个小团体，计算团体数
思路
- 用v，course记录当前小团体人员分布，兴趣分布
- 每次读取的时候，遍历现有小团体，把重合团体编号存入一个vector merge
- 如果!merge.size(), 则新建一个小团体
- 否则合并小团体
- 调试的时候发现一个bug
- merge.erase之后存在merge中的id就不再对应真实id，需要处理一下
code
/*
* @Author: gunjianpan
* @Date: 2018-09-29 19:58:35
* @Last Modified by: gunjianpan
* @Last Modified time: 2018-09-29 21:15:34
*/
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
const int MAXN = 1010;
std::vector<int> pre[MAXN], merges;
std::vector<vector<int> > v, course;
bool vis[MAXN] = {false};
bool sortnum(vector<int> a, vector<int> b) {
return a.size() == b.size() || a.size() > b.size();
}
int main(int argc, char const *argv[]) {
int n, num, temp, count = 0;
cin >> n;
for (int i = 0; i < n; ++i) {
scanf("%d:", &num);
merges.clear();
fill(vis, vis + MAXN, false);
count = 0;
for (int j = 0; j < num; ++j) {
cin >> temp;
pre[i].push_back(temp);
for (int k = 0; k < v.size(); ++k)
if (!vis[k] && std::find(course[k].begin(), course[k].end(), temp) !=
course[k].end()) {
merges.push_back(k);
vis[k] = true;
}
}
if (!merges.size()) {
std::vector<int> top;
top.push_back(i);
v.push_back(top);
course.push_back(pre[i]);
} else {
sort(merges.begin(), merges.end());
int top = merges[0];
v[top].push_back(i);
course[top].insert(course[top].end(), pre[i].begin(), pre[i].end());
for (int j = 1; j < merges.size(); ++j) {
v[top].insert(v[top].end(), v[merges[j] - count].begin(),
v[merges[j] - count].end());
course[top].insert(course[top].end(), course[merges[j] - count].begin(),
course[merges[j] - count].end());
v.erase(v.begin() + merges[j] - count);
course.erase(course.begin() + merges[j] - count);
++count;
}
}
}
cout << v.size() << endl;
sort(v.begin(), v.end(), sortnum);
for (int i = 0; i < v.size(); ++i) {
if (i) cout << ' ';
cout << v[i].size();
}
return 0;
}