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Werewolf
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 262144/262144 K (Java/Others)
Total Submission(s): 448 Accepted Submission(s): 85

Problem Description
“The Werewolves” is a popular card game among young people.In the basic game, there are 2 different groups: the werewolves and the villagers.

Each player will debate a player they think is a werewolf or not.

Their words are like “Player x is a werewolf.” or “Player x is a villager.”.

What we know is :

1. Villager won’t lie.

2. Werewolf may lie.

Of cause we only consider those situations which obey the two rules above.

It is guaranteed that input data exist at least one situation which obey the two rules above.

Now we can judge every player into 3 types :

1. A player which can only be villager among all situations,

2. A player which can only be werewolf among all situations.

3. A player which can be villager among some situations, while can be werewolf in others situations.

You just need to print out the number of type-1 players and the number of type-2 players.

No player will talk about himself.

Input
The first line of the input gives the number of test cases T.Then T test cases follow.

The first line of each test case contains an integer N,indicating the number of players.

Then follows N lines,i-th line contains an integer x and a string S,indicating the i-th players tell you,”Player x is a S.”

limits:

1≤T≤10

1≤N≤100,000

1≤x≤N

S∈ {“villager”.”werewolf”}

Output
For each test case,print the number of type-1 players and the number of type-2 players in one line, separated by white space.

Sample Input
1
2
2 werewolf
1 werewolf

Sample Output
0 0
基环树，基环内向树，基环外向树：
https://blog.csdn.net/Q1410136042/article/details/81152191

赛场上思路出来了，一直没有想到怎么写出来，还是写得少，继续码代码吧

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const int inf = 0x3f3f3f3f;
const int N = 1000005;
typedef struct Node{
    vector<int>ve;
    int iswolf;
    int nxt;
}Node;
Node edge[N];
int b[N];
bool iswolf[N];
int join(int x)
{
    int i = x;
    while(x != b[x])
        x = b[x];
    while(i != b[i])
    {
        int t = b[i];
        b[i] = x;
        i = t;
    }
    return x;
}
void bing(int x,int y)
{
    int p = join(x);
    int q = join(y);
    if(p != q){
        b[p] = b[q];
    }
}

void dfs(int num)
{
    iswolf[num] = true;
    if(edge[num].ve.size() == 0){
        return ;
    }
    int len = edge[num].ve.size();
    for(int i = 0;i < len;++i)
    {
        dfs(edge[num].ve[i]);
    }
}

int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n;
        scanf("%d",&n);
        for(int i = 1;i <= n;++i)
            b[i] = i;
        for(int i = 0;i < n;++i)
            edge[i + 1].ve.clear();
        for(int i = 0;i < n;++i)
        {
            char s[15];int m;
            scanf("%d %s",&m,s);
            edge[i + 1].nxt = m;
            if(strcmp(s,"werewolf") == 0){
                edge[i + 1].iswolf = 1;
            }
            else{
                edge[i + 1].iswolf = 0;
                bing(i + 1,m);
                edge[m].ve.push_back(i + 1);
            }
        }
        //system("pause");
        memset(iswolf,false,sizeof(iswolf));
        //printf("0\n");
        for(int i = 0;i < n;++i)
        {
            if(edge[i + 1].iswolf == 1)
            {
                int num = edge[i + 1].nxt;
                if(join(num) == join(i + 1)){
                     dfs(num);
                }
            }
        }
        int cnt = 0;
        for(int i = 1;i <= n;++i)
        {
            if(iswolf[i]){
                cnt++;
            }
        }
        printf("0 %d\n",cnt);
    }
    return 0;
}