POJ 1611 The Suspects

题意：

思路：

const
maxn=30000;
var
a,f:array [0..maxn] of longint;
o,k,i,j,n,m,ans:longint;

function father(x:longint):longint;
begin
if f[x]=x then father:=x
else father:=father(f[x]);
f[x]:=father;
end;

begin
readln(n,m);
while (n<>0) or (m<>0)  do
begin
ans:=0;
for i:=0 to n do
f[i]:=i;
for j:=1 to m do
begin
read(o);
read(a[0]);
for i:=1 to o-1 do
begin
read(a[i]);

f[father(a[i-1])]:=father(a[i]);
end;
readln;
end;
for i:=0 to n do
if father(f[i])=father(f[0]) then inc(ans);
writeln(ans);
readln(n,m);
end;
end.