基礎款並查集練習題
// 13'11"
#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 10;
int p[N], f[N];
void init()
{
for(int i = 1; i <= N; ++ i)
p[i] = i;
}
int find(int x)
{
if(x != p[x]) p[x] = find(p[x]);
return p[x];
}
void merge(int a, int b)
{
int fa = find(a), fb = find(b);
if(fa != fb) p[fa] = fb;
}
void fenzhi()
{
int cnt1 = 0, cnt2 = 0;
for(int i = 1; i <= N; ++ i)
{
if(p[i] == i && f[i] == true) ++ cnt1;
if(f[i] == true) ++ cnt2;
}
cout << cnt2 << " " << cnt1 << endl;
}
int main()
{
int n;
cin >> n;
init();
for(int i = 1; i <= n; ++ i)
{
int k;
scanf("%d",&k);
int tmp;
scanf("%d",&tmp);
f[tmp] = true;
for(int j = 1; j < k; ++ j)
{
int tmp2;
scanf("%d",&tmp2);
f[tmp2] = true;
merge(tmp,tmp2);
}
}
int q;
cin >> q;
fenzhi();
for(int i = 1; i <= q; ++ i)
{
int a, b;
scanf("%d%d",&a,&b);
if(find(a) == find(b)) cout << "Y\n";
else cout << "N\n";
}
return 0;
}