【无标题】

1.2026 L9 梆梆不梆梆

https://pintia.cn/problem-sets/2033384889317560320/exam/problems/type/7?problemSetProblemId=2033384889577603095

使用并查集及路径压缩，板子要记牢

#include<bits/stdc++.h>
using namespace std;
#define M 10004
int n,m,fa[M];
int ff(int x)
{
	if(x!=fa[x])
		fa[x]=ff(fa[x]);
		return fa[x];	
}
signed main()
{
	priority_queue<int,vector<int>,greater<int> > q[M];
	priority_queue<int,vector<int>,greater<int> > ans;
	cin>>n>>m;
	int T=n;
	for(int i=1;i<=m;i++)
		fa[i]=i;
	while(T--)
	{
		int len,num,num1;
		cin>>len>>num1;
		for(int i=2;i<=len;i++)
		{
			cin>>num;
			int x=ff(num1);
			int y=ff(num);
			if(x!=y)
				fa[x]=y;	
		}
	}
	for(int i=1;i<=m;i++)	
	{
//		cout<<i<<" "<<ff(i)<<endl;
		q[ff(i)].push(i);
	}
	int sum=0;
	for(int i=1;i<=m;i++)
		if(ff(i)==i)
		{
			ans.push(q[i].top());
			sum++;
			}	
	while(!ans.empty())
	{
		cout<<ans.top();
		ans.pop();
		sum--;
		if(sum!=0)
			cout<<" ";
	}
//	cout<<"d";
	return 0;		
}

2.2023 L1-7 谷歌的招聘

https://pintia.cn/problem-sets/2037056710707339264/exam/problems/type/7?problemSetProblemId=2037056710849945605

欧拉筛写了一半