PAT (Advanced Level) Practise 1107 Social Clusters (30)

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:

Ki: hi[1] hi[2] ... hi[Ki]

where Ki (>0) is the number of hobbies, and hi[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

题意：有n个人，每个人有k个爱好，有相同爱好的为一类，问一共有几类，每类各有多少人

解题思路：把每个爱好分配给一个人，相同爱好的人用并查集合并一下

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <vector>
#include <bitset>

using namespace std;

#define LL long long
const int INF = 0x3f3f3f3f;

int n,f[1005],vis[1005],cnt[1005];
int k,a;

int Find(int x)
{
return f[x]==x?x:f[x]=Find(f[x]);
}

int main()
{
while(~scanf("%d",&n))
{
for(int i=1;i<=n;i++)f[i]=i;
memset(vis,0,sizeof vis);
memset(cnt,0,sizeof cnt);
for(int i=1;i<=n;i++)
{
scanf("%d:",&k);
for(int j=1;j<=k;j++)
{
scanf("%d",&a);
if(!vis[a]) vis[a]=i;
else
{
int aa=Find(i);
int bb=Find(vis[a]);
if(aa!=bb) f[aa]=bb;
}
}
}
int sum=0;
for(int i=1;i<=n;i++)
{
if(f[i]==i) sum++;
int aa=Find(i);
cnt[aa]++;
}
sort(cnt+1,cnt+1+n,greater<int>());
printf("%d\n%d",sum,cnt[1]);
for(int i=2;i<=sum;i++) printf(" %d",cnt[i]);
printf("\n");
}
return 0;
}