1114 Family Property (25分)
This time, you are supposed to help us collect the data for family-owned property. Given each person’s family members, and the estate（房产）info under his/her own name, we need to know the size of each family, and the average area and number of sets of their real estate.
Input Specification:

Each input file contains one test case. For each case, the first line gives a positive integer N (≤1000). Then N lines follow, each gives the infomation of a person who owns estate in the format:
ID Father Mother k Child
​1
​​ ⋯Child
​k
​​ M
​estate
​​ Area
where ID is a unique 4-digit identification number for each person; Father and Mother are the ID’s of this person’s parents (if a parent has passed away, -1 will be given instead); k (0≤k≤5) is the number of children of this person; Child
​i
​​ 's are the ID’s of his/her children; M
​estate
​​ is the total number of sets of the real estate under his/her name; and Area is the total area of his/her estate.
Output Specification:

For each case, first print in a line the number of families (all the people that are related directly or indirectly are considered in the same family). Then output the family info in the format:
ID M AVG
​sets
​​ AVG
​area
​​
where ID is the smallest ID in the family; M is the total number of family members; AVG
​sets
​​ is the average number of sets of their real estate; and AVG
​area
​​ is the average area. The average numbers must be accurate up to 3 decimal places. The families must be given in descending order of their average areas, and in ascending order of the ID’s if there is a tie.
Sample Input:

10
6666 5551 5552 1 7777 1 100
1234 5678 9012 1 0002 2 300
8888 -1 -1 0 1 1000
2468 0001 0004 1 2222 1 500
7777 6666 -1 0 2 300
3721 -1 -1 1 2333 2 150
9012 -1 -1 3 1236 1235 1234 1 100
1235 5678 9012 0 1 50
2222 1236 2468 2 6661 6662 1 300
2333 -1 3721 3 6661 6662 6663 1 100
Sample Output:

3
8888 1 1.000 1000.000
0001 15 0.600 100.000
5551 4 0.750 100.000

#include<iostream>
#include<set>
#include<vector>
#include<map>
#include<algorithm>
using namespace std;
const int maxn = 10000;
int pre[maxn];
struct node {//存储开始输入的人的基本信息int id, house;double area;
};
struct family {//输出的家庭结构体int id, number;double house, area;
};
bool cmp(family a, family b)//自定义比较函数
{if (a.area != b.area)return a.area > b.area;else return a.id < b.id;
}
int find(int x)//并查集模板，查找
{while (x != pre[x]) x = pre[x];return x;
}
void merge(int x, int y)//并查集模板，合并
{int a = find(x);int b = find(y);if (a != b) pre[a] = b;
}
int main()
{int n, x;cin >> n;set<int>s;//存储每人的编号，默认升序map<int, node>nodes;//记录人的房产信息for (int i = 0; i < maxn; i++)pre[i] = i;//初始化pre数组for (int i = 0; i < n; i++){int id, p1, p2, k, house, id1;//分别记录编号 父 母 k 孩子1 ... 孩子k 房产套数double area;// 总面积cin >> id >> p1 >> p2 >> k;s.insert(id);//插入idif (p1 != -1)//有爸爸{s.insert(p1);merge(id, p1);}if (p2 != -1)//有妈妈{s.insert(p2);merge(id, p2);}for (int j = 0; j < k; j++)//随后的家庭成员{cin >> id1;s.insert(id1);merge(id1, id);}cin >> house >> area;nodes[id] = node{ id,house,area };//记录该人的家庭信息}set<int>s1;//记录家庭编号（也可以理解记录着每个家庭的老大）map<int, vector<int>>m;//记录家庭编号（）和成员编号for (auto it = s.begin(); it != s.end(); it++){int fa = find(*it);m[fa].push_back(*it);s1.insert(fa);}cout << s1.size() << endl;//输出家庭的个数vector<family>v1;for (auto it = s1.begin(); it != s1.end(); it++){int fa = *it;double house = 0, area = 0;for (auto tmp = 0; tmp < m[fa].size(); tmp++)//将每个家庭的成员及其房产计算汇总，放入family结构体中{house += nodes[m[fa][tmp]].house;area += nodes[m[fa][tmp]].area;}v1.push_back(family{ m[fa][0],int(m[fa].size()),house * 1.0 / (int)m[fa].size(),area * 1.0 / (int)m[fa].size() });}sort(v1.begin(), v1.end(), cmp);//进行排序for (int i = 0; i < v1.size(); i++) {printf("%04d %d %.3lf %.3lf", v1[i].id, v1[i].number, v1[i].house, v1[i].area);if (i < v1.size() - 1) puts("");}
}