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

-------------------------------------------------

题意：喜欢同样活动的人属于一个集合，问一共有多少个集合，递减输出每个集合里的人数。

思路：并查集

AC代码：

#include <iostream>#include <algorithm>#include <cstdio>#include <cstdlib>#include <cstring>#include <string>#include <vector>#include <queue>#include <stack>using namespace std;bool comp(int a,int b){    return a>b;}int power[1010]={0};int book[1010]={0};int father[1010];int findRoot(int x)//找到集合的根{    while(x!=father[x])    {        x=father[x];    }    return x;}void init(int n)//初始化{    int i;    for(i=1;i<=n;i++)        father[i]=i;}void Union(int a,int b)//合并元素a，b所在的集合{    int roota,rootb;    roota=findRoot(a);    rootb=findRoot(b);    father[roota]=rootb;}int main(){    //freopen("in.txt","r",stdin);    int N;    cin>>N;    init(N);    for(int i=1;i<=N;i++)    {        int k;        scanf("%d:",&k);        int j;        for(j=1;j<=k;j++)        {            int h;            cin>>h;            if(book[h]==0)            {                book[h]=i;            }            else            {                Union(i,book[h]);            }        }    }    int cou=0;    for(int i=1;i<=N;i++)    {        if(father[i]==i)            cou++;    }    cout<<cou<<"\n";    for(int i=1;i<=N;i++)    {        int t=findRoot(i);        power[t]++;    }    sort(power+1,power+1+N,comp);        printf("%d",power[1]);    for(int i=2;i<=cou;i++)    {        printf(" %d",power[i]);    }    return 0;}

笔记：

1.sort也可以排序数组，递增时候加个comp。

bool comp(int a,int b)
{
    return a>b;
}