Dual connected components of undirected graphs (tarjan template)

#include <iostream> #include <cstdio> #include <algorithm> #include <cstring> #include < Stack> #include <vector>using namespace std; #define MAXN 7500#define inf 0x3f3f3f3fint n,m;int G[MAXN][MAXN]; int Clock;int low[maxn],pre[maxn];stack<int>s;int bc;vector<int>bcc[maxn];int dfs (int u,int fa) {low[u]=p     Re[u]=++clock;     S.push (U);        for (int v=1;v<=n;v++) {if (!g[u][v]) continue;            if (!pre[v]) {int Lowv=dfs (V,U);            Low[u]=min (LOW[U],LOWV);                if (Lowv>=pre[u]) {bc++;                Bcc[bc].clear ();                int tmp=-1;                    while (!s.empty ()) {tmp=s.top ();                    S.pop ();                    Bcc[bc].push_back (TMP);                if (tmp==u) break;  } if (tmp!=-1) S.push (TMP); Cut the top to add back, arbitrarily cut the top is at least two different two components of the common point}} else if (pre[v]<pre[u]&&fa!=v) {low[u]=min (   LOW[U],PRE[V]);     }} return low[u];}    void Inital () {clock=0;    bc=0;    memset (pre,0,sizeof Pre);    memset (low,inf,sizeof low);    while (!s.empty ()) {s.pop ();    }}int Main () {int u,v;    Freopen ("In.txt", "R", stdin);        while (~SCANF ("%d%d", &n,&m)) {inital ();            for (int i=0;i<m;i++) {scanf ("%d%d", &u,&v);        G[u][v]=g[v][u]=1;        } for (int i=1;i<=n;i++) {if (!pre[i]) DFS (I,-1);        } for (int i=1;i<=n;i++) {printf ("%d%d\n", pre[i],low[i]);        } printf ("Below is the point Unicom component%d:\n", BC);            for (int i=1;i<=bc;i++) {printf ("%d:", i);            for (int j=0;j<bcc[i].size (); j + +) {printf ("%d", bcc[i][j]);        } printf ("\ n"); }    }}

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Dual connected components of undirected graphs (tarjan template)