1 

 1 #include <bits/stdc++.h>
 2 #define up(i,l,r) for(register int i = (l); i <= (r); i++)
 3 #define dn(i,l,r) for(register int i = (l); i >= (r); i--)
 4 #define ll long long
 5 using namespace std;
 6 template <typename T>void in(T &x){
 7     x = 0; T f = 1; char ch = getchar();
 8     while(!isdigit(ch)) {if(ch == '-') f = -1; ch = getchar();}
 9     while( isdigit(ch)) {x = 10 * x + ch - 48; ch = getchar();}
10     x *= f;
11 }
12 template <typename T>void put(T x){
13     //if(x < 0) x = -x,putchar('-');
14     if(x > 9) put(x/10);
15     putchar(x%10 + 48);
16 }
17 const int N = 100005;
18 int n;
19 
20 struct edge{
21     int v,nxt;
22 }e[N]; int tot,head[N];
23 
24 void add(int u,int v){ e[++tot] = (edge){v,head[u]}; head[u] = tot;}
25 
26 int dfn[N],low[N],sn,cnt,size[N],belong[N],f[N],maxn[N];
27 bool instack[N],vis[N];
28 
29 stack<int>s;
30 
31 void debug(){
32     int t;
33     while(!s.empty()){
34         t = s.top(); put(t); putchar(' ');
35         s.pop();
36     }
37 }
38 
39 void tarjan(int u){
40     
41     dfn[u] = low[u] = ++sn;
42     s.push(u);
43     instack[u] = 1;
44     //if(u == 3) debug();
45     for(int i = head[u]; i; i = e[i].nxt){
46         int v = e[i].v;
47         if(!dfn[v]){
48             tarjan(v);
49             low[u] = min(low[u],low[v]);
50         }
51         else if(instack[v]) low[u] = min(low[u],dfn[v]);
52     }
53     int t = -1;
54     if(low[u] == dfn[u]){
55         ++cnt;
56         while(t != u){
57             t = s.top();
58             s.pop();
59             instack[t] = 0;
60             belong[t] = cnt; 
61             ++size[cnt];
62         }
63     }
64 }
65 
66 void dfs(int u){
67     if(f[belong[u]]) return;
68     f[belong[u]] = size[belong[u]];
69     for(int i = head[u]; i; i = e[i].nxt){
70         int v = e[i].v;
71         //if(vis[belong[v]]) continue;
72         if(belong[u] == belong[v]) continue;
73         dfs(v); //vis[belong[v]] = 1;
74         f[belong[u]] += f[belong[v]];
75     }
76 }
77 
78 int main(){
79     int v;
80     in(n);
81     up(i,1,n){
82         in(v);
83         add(i,v);
84     }
85     up(i,1,n) if(!dfn[i]) tarjan(i);
86     up(i,1,n) if(!vis[i]) dfs(i);
87     up(i,1,n){
88         put(f[belong[i]]); 
89         putchar('\n');
90     }
91     return 0;
92 }

 

 

posted @ 2019-05-11 11:26  陈星卿  阅读(139)  评论(0)    收藏  举报