This question is mostly online solution is the use of disjoint-set, I think we can also consider using the graph traversal do, every family will be seen as a figure connected, then we need to do is go through each connected graph and each of their statistical area connectivity graph and estate can use the vector container to store the id of all, from small to large and then sort, we can ensure that every family is the family of id smallest id. code show as below:
#include<cstdio>
#include<vector>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
struct people{
int estate,area;
people()
{
estate=0;
area=0;
}
}p[10010];
struct family{
int id, num;
double sets,area;
}f[1010];
vector<int> Adj[10010],human;
bool vis[10010]={false};
int familynum=0;
bool cmp(family a,family b)
{
if(a.area!=b.area) return a.area>b.area;
else return a.id<b.id;
}
void deal(int parent,int child)
{
if(!vis[child])
{
vis[child]=true;
human.push_back(child);
}
if(parent==-1) return;
Adj[parent].push_back(child);
Adj[child].push_back(parent);
if(!vis[parent])
{
vis[parent]=true;
human.push_back(parent);
}
}
void BFS(int root)
{
queue<int> q;
q.push(root);
vis[root]=true;
while(!q.empty())
{
int k=q.front();
q.pop();
f[familynum].num++;
f[familynum].sets+=p[k].estate;
f[familynum].area+=p[k].area;
for(int i=0;i<Adj[k].size();i++)
if(!vis[Adj[k][i]])
{
q.push(Adj[k][i]);
vis[Adj[k][i]]=true;
}
}
}
int main ()
{
int n;
scanf("%d",&n);
for(int i=0;i<n;i++)
{
int a,b,c,d,e;
scanf("%d %d %d %d",&a,&b,&c,&d);
deal(b,a);
deal(c,a);
for(int j=0;j<d;j++)
{
scanf("%d",&e);
deal(a,e);
}
scanf("%d %d",&p[a].estate,&p[a].area);
}
sort(human.begin(),human.end());
memset(vis,false,sizeof(vis));
for(int i=0;i<human.size();i++)
{
if(!vis[human[i]])
{
f[familynum].id=human[i];
BFS(human[i]);
f[familynum].sets=(double)(f[familynum].sets*1.0/f[familynum].num);
f[familynum].area=(double)(f[familynum].area*1.0/f[familynum].num);
familynum++;
}
}
sort(f,f+familynum,cmp);
printf("%d\n",familynum);
for(int i=0;i<familynum;i++)
{
printf("%04d %d %.3f %.3f\n",f[i].id,f[i].num,f[i].sets,f[i].area);
}
return 0;
}