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 (≤). 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) 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

参考柳神的解法，使用并查集进行求解。

#include <cstdio>
#include <algorithm>
using namespace std;
struct DATA {
    int id, fid, mid, num, area;
    int cid[10];
}data[1005];
struct node {
    int id, people;
    double num, area;
    bool flag = false;
}ans[10000];
int father[10000];
bool visit[10000];
int find(int x) {
    while(x != father[x])
        x = father[x];
    return x;
}
void Union(int a, int b) {
    int faA = find(a);
    int faB = find(b);
    if(faA > faB)
        father[faA] = faB;
    else if(faA < faB)
        father[faB] = faA;
}
int cmp1(node a, node b) {
    if(a.area != b.area)
        return a.area > b.area;
    else
        return a.id < b.id;
}
int main() {
    int n, k, cnt = 0;
    scanf("%d", &n);
    for(int i = 0; i < 10000; i++)
        father[i] = i;
    for(int i = 0; i < n; i++) {
        scanf("%d %d %d %d", &data[i].id, &data[i].fid, &data[i].mid, &k);
        visit[data[i].id] = true;
        if(data[i].fid != -1) {
            visit[data[i].fid] = true;
            Union(data[i].fid, data[i].id);
        }
        if(data[i].mid != -1) {
            visit[data[i].mid] = true;
            Union(data[i].mid, data[i].id);
        }
        for(int j = 0; j < k; j++) {
            scanf("%d", &data[i].cid[j]);
            visit[data[i].cid[j]] = true;
            Union(data[i].cid[j], data[i].id);
        }
        scanf("%d %d", &data[i].num, &data[i].area);
    }
    for(int i = 0; i < n; i++) {
        int id = find(data[i].id);
        ans[id].id = id;
        ans[id].num += data[i].num;
        ans[id].area += data[i].area;
        ans[id].flag = true;
    }
    for(int i = 0; i < 10000; i++) {
        if(visit[i])
            ans[find(i)].people++;
        if(ans[i].flag)
            cnt++;
    }
    for(int i = 0; i < 10000; i++) {
        if(ans[i].flag) {
            ans[i].num = (double)(ans[i].num * 1.0 / ans[i].people);
            ans[i].area = (double)(ans[i].area * 1.0 / ans[i].people);
        }
    }
    sort(ans, ans + 10000, cmp1);
    printf("%d
", cnt);
    for(int i = 0; i < cnt; i++)
        printf("%04d %d %.3f %.3f
", ans[i].id, ans[i].people, ans[i].num, ans[i].area);
    return 0;
}