第十章并查集 4 AcWing 1597. 社会集群

浅浅的花香味﹌ 2024-03-31 12:22 78阅读 0赞

## 第十章 并查集 4 AcWing 1597. 社会集群 ##

### 原题链接 ###

[AcWing 1597. 社会集群][AcWing 1597.]

### 算法标签 ###

并查集

### 思路 ###

使用并查集依题意模拟

### 代码 ###

#pragma GCC optimize(2)
    #pragma GCC optimize(3)
    #include<bits/stdc++.h>
    #define int long long
    #define xx first
    #define yy second
    #define ump unordered_map
    #define us unordered_set
    #define pq priority_queue
    #define rep(i, a, b) for(int i=a;i<b;++i)
    #define Rep(i, a, b) for(int i=a;i>=b;--i)
    using namespace std;
    typedef pair<int, int> PII;
    const int N=10005, inf=0x3f3f3f3f3f3f3f3f, mod=1e9+7;
    const double Exp=1e-8;
    //int t, n, m, cnt, ans; 
    int n, k, p[N], h, c[N];
    vector<int> ho[N];
    bool st[N];
    inline int rd(){
       int s=0,w=1;
       char ch=getchar();
       while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
       while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
       return s*w;
    }
    void put(int x) {
        if(x<0) putchar('-'),x=-x;
        if(x>=10) put(x/10);
        putchar(x%10^48);
    }
    int find(int x){
        if(x!=p[x]){
            return p[x]=find(p[x]);
        }return p[x];
    }
    signed main(){
    	ios::sync_with_stdio(false);
    	cin.tie(0);
    	cout.tie(0);
    // 	n=rd();
    	scanf("%lld", &n);
    	rep(i, 0, n){
    	    scanf("%lld:", &k);
    	   //k=rd();
    	   while(k--){
    	       // h=rd();
    	       scanf("%lld", &h);
    	       ho[h].push_back(i);
    	    }
    	}
    	rep(i, 0, n){
    	    p[i]=i;
    	}
    	int cnt=0;
    	rep(i, 0, 1000+1){
    	    rep(j, 0, ho[i].size()){
    	    	// 与首元素合并或相邻两两合并皆可
    	        int a=find(ho[i][0]), b=find(ho[i][j]);
                p[a]=b;
                cnt++;  
    	    }
    	}
    	rep(i, 0, n){
    	    c[find(i)]++;
    	}
    	sort(c, c+n, greater<int>());
    	int cc=0;
    	while(c[cc]){
    	    cc++;
    	}
    	// 	等价于 while(c[++cc]);
    	printf("%lld\n", cc);
    	printf("%lld", c[0]);
    	rep(i, 1, cc){
    	    printf(" %lld", c[i]);
    	}
    	return 0;
    }

### 参考文献 ###

[AcWing 1597. 社会集群（PAT甲级辅导课）y总视频讲解][AcWing 1597. _PAT_y]

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[AcWing 1597.]: https://www.acwing.com/problem/content/1599/
[AcWing 1597. _PAT_y]: https://www.acwing.com/video/1271/
[9cb4cb80a18345158f8a69e2f196e5b9.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/6fe7701aff294cd490faaf280116c489.png