PAT-1107 Social Clusters (30 分)

原题链接：https://pintia.cn/problem-sets/994805342720868352/problems/994805361586847744

 

8
3: 2 7 10
1: 4
2: 5 3
1: 4
1: 3
1: 4
4: 6 8 1 5
1: 4

 

3
4 3 1

题解：把每个爱好的合并在一起，每个集合的father节点计数--->总的圈子数以及圈子里的人数，

#include <string.h>
#include <stdio.h>
#include <algorithm>
#include <math.h>
#include <iostream>
using namespace std;
const int maxn=1000+5;
int father[maxn], hobby[maxn]={0}, isRoot[maxn]={0};

void init(int n){
    for(int i=1;i<=n;i++) father[i]=i,isRoot[i]=0;
}

int find(int x){
    int a=x;
    while(x!=father[x]){
        x=father[x];
    }
    while(a!=father[a]){ //路径压缩 
        int z=a;
        a=father[a];
        father[z]=x;
    }
    return x;
}

void Union(int u, int v){
    int a=find(u);
    int b=find(v);
    if(a!=b){
        father[a]=b;
    }
}

bool cmp(int x, int y){
    return x>y;
}


int main(){
    int n,k,h;
    scanf("%d",&n);
    init(n);
    for(int i=1;i<=n;i++) {
        scanf("%d:",&k);
        for (int j=0;j<k;j++){
            scanf("%d",&h);
            if(hobby[h]==0) hobby[h]=i;
            Union(i, hobby[h]);
        }
    }
    for(int i=1;i<=n;i++)
        isRoot[find(i)]++;
    int ans=0;
    for(int i=1;i<=n;i++)
        if(isRoot[i])
            ans++;
    printf("%d
",ans);
    sort(isRoot+1, isRoot+1+n,cmp);
    for(int i=1;i<=ans;i++){
        printf("%d",isRoot[i]);
        if(i<ans) printf(" ");
    }
    return 0;
    
}

菠萝的版本

def person_hobby2():
    n=int(input())
    hobby_person={}
    for i in range(n):
        person_hobby=set(map(int,input().split()[1:]))
        temp=[]
        for j,k in hobby_person.items():
            if not person_hobby.isdisjoint(k[0]):
                temp.append(j)
        hobby_person[i]=[person_hobby,1]
        for j in temp:
            hobby_person[i][0].update(hobby_person[j][0])
            hobby_person[i][1]+=hobby_person[j][1]
            del hobby_person[j]
    print(len(hobby_person))
    ans=[]
    for i in hobby_person.values():
        ans.append(i[1])
    print(' '.join(map(str,sorted(ans,reverse=True))))    

if __name__ == "__main__":
    person_hobby2()