POJ 1236 Network of Schools - 缩点

/*
* @Author: chenkexing
* @Date:   2018-09-05 11:05:14
* @Last Modified by:   chenkexing
* @Last Modified time: 2018-09-07 20:25:39
*/
#include <algorithm>
#include  <iterator>
#include  <iostream>
#include   <cstring>
#include   <cstdlib>
#include   <iomanip>
#include    <bitset>
#include    <cctype>
#include    <cstdio>
#include    <string>
#include    <vector>
#include     <stack>
#include     <cmath>
#include     <queue>
#include      <list>
#include       <map>
#include       <set>
#include   <cassert>
using namespace std;
//#pragma GCC optimize(3)
//#pragma comment(linker, "/STACK:102400000,102400000")  //c++
#define lson (l , mid , rt << 1)
#define rson (mid + 1 , r , rt << 1 | 1)
#define debug(x) cerr << #x << " = " << x << "\n";
#define pb push_back
#define pq priority_queue



typedef long long ll;
typedef unsigned long long ull;

typedef pair<ll ,ll > pll;
typedef pair<int ,int > pii;
typedef pair<int,pii> p3;

//priority_queue<int> q;//这是一个大根堆q
//priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q
#define fi first
#define se second
//#define endl ‘\n‘

#define OKC ios::sync_with_stdio(false);cin.tie(0)
#define FT(A,B,C) for(int A=B;A <= C;++A)  //用来压行
#define REP(i , j , k)  for(int i = j ; i <  k ; ++i)
//priority_queue<int ,vector<int>, greater<int> >que;

const ll mos = 0x7FFFFFFF;  //2147483647
const ll nmos = 0x80000000;  //-2147483648
const int inf = 0x3f3f3f3f;       
const ll inff = 0x3f3f3f3f3f3f3f3f; //18
const int mod = 1e9+7;
const double esp = 1e-8;
const double PI=acos(-1.0);



template<typename T>
inline T read(T&x){
    x=0;int f=0;char ch=getchar();
    while (ch<‘0‘||ch>‘9‘) f|=(ch==‘-‘),ch=getchar();
    while (ch>=‘0‘&&ch<=‘9‘) x=x*10+ch-‘0‘,ch=getchar();
    return x=f?-x:x;
}


/*-----------------------showtime----------------------*/
            const int maxn = 400;
            vector<int>mp[maxn];
            int dfn[maxn],low[maxn],vis[maxn],col[maxn];
            int in[maxn],out[maxn];
            int tot,cnt;
            stack<int>S;
            void tarjan(int x){
                low[x] = dfn[x] = ++tot;
                S.push(x);vis[x] = 1;
                for(int i=0; i<mp[x].size(); i++){
                    int v = mp[x][i];
                    if(!dfn[v]){
                        tarjan(v);
                        low[x] = min(low[x],low[v]);
                    }
                    else if(vis[v]){
                        low[x] = min(low[x], dfn[v]);
                    }
                } 
                if(low[x] == dfn[x]){
                    cnt++;
                    while(true){
                        int now = S.top();
                        S.pop();
                        col[now] = cnt;
                        vis[now] = 0;
                        if(now == x)break;
                    }
                }
            }
int main(){
            int n;
            while(~scanf("%d", &n)){
                for(int i=1; i<=n; i++){
                    mp[i].clear();
                    dfn[i] = low[i] = vis[i] = col[i] = 0;
                    in[i] = out[i] = 0;
                    tot = cnt = 0;
                }
                while(!S.empty())S.pop();

                for(int i=1; i<=n; i++){
                    int x;
                    while(scanf("%d", &x) && x){
                        mp[i].pb(x);
                    }
                }

                for(int i=1; i<=n; i++){
                    if(dfn[i] == 0){
                        tarjan(i);
                    }
                }

                for(int i=1; i<=n; i++){
                    for(int j=0; j<mp[i].size(); j++){
                        int u = i,v = mp[i][j];
                        if(col[u] != col[v]){
                            out[col[u]]++;
                            in[col[v]]++;
                        }
                    }
                }
                // debug(cnt);
                
                int ans1 = 0,ans2 = 0;
                for(int i=1; i<=cnt; i++){
                    if(in[i] == 0)ans1++;
                    if(out[i] == 0)ans2++;
                }
                if(cnt==1)
                    printf("1\n0\n");
                else printf("%d\n%d\n", ans1,max(ans1,ans2));
            }
            return 0;
}