P3469 cut point of application

https://www.luogu.org/problem/P3469

That is a subject of the blockade points, which will lead to point (to) even unreasonable;

Cutpoint with tarjan seeking, if the cut point is a point, the point impassable number is (multiplication rule) is multiplied by the size of the subtrees son + n-1;

If the point is not cut n-1;

#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn=5e5+10;
int pre[maxn*2],last[maxn],other[maxn*2],l;
int n,m;
void add(int x,int y)
{
    l++;
    pre[l]=last[x];
    last[x]=l;
    other[l]=y;
}
bool vis[maxn];
long long ans[maxn];
int dfn[maxn],cnt,low[maxn],siz[maxn],fa[maxn];
void dfs(int x)
{
    dfn[x]=low[x]=++cnt;
    vis[x]=1;
    siz[x]=1;
    int ss=0;
    for(int p=last[x];p;p=pre[p])
    {
        int v=other[p];
        if(!vis[v])
        {
            fa[v]=x;
            dfs(v);
            siz[x]+=siz[v];
            Low [X] = min (Low [X], Low [V]);
             IF (Low [V]> = DFN [X] && FA [X] = V!) // the son node can not bypass this point reaches above node 
            { 
                ANS [X] + = ( Long  Long ) SS * SIZ [V]; // have already been calculated are blocked by the sons now 
                SS = + SIZ [V]; // update 
            } 
        } 
        the else Low [X ] = min (Low [X], DFN [V]); 
    } 
    ANS [X] + = ( Long  Long ) (N- . 1 ); 
    ANS [X] + = ( Long  Long ) SS * (n--SS- . 1 ); //Blocked son multiplied not blocked 
} 

int main () 
{ 
    Scanf ( " % D% D " , & n-, & m);
     for ( int I = . 1 ; I <= m; I ++ ) 
    { 
        int A, B ; 
        Scanf ( " % D% D " , & A, & B); 
        the Add (A, B); the Add (B, A); 
    } 
    DFS ( . 1 );
     for ( int I = . 1 ; I <= n-; I ++ ) 
    { 
        the printf ( " % LLD \ n- " , ANS [I] * 2 ); //Point ordered 
    }
     return  0 ; 
}