POJ 1236 Network of schools

11:

Strong Unicom Component

First: First find out how many points in the graph, even the answer to a, is 0.

Second: First Tarjan, the point with a degree of 0 n a point with a degree of 0 m

We only have this N m connected to the answer for Max (n,m) can be 22 connected

CODE:

#include <cstdio> #include <iostream> #include <vector> #include <stack> #include <algorithm > #include <string.h>using namespace std;const int N =111;vector<int> g[n];int dfn[n],low[n],belong[n], dfs_clock,scc_cnt;stack<int> s;void dfs (int u) {    dfn[u]=low[u]=++dfs_clock;    s.push (U);     for (int i=0;i<g[u].size (); i++)     {        int v=g[u][i];    &NB Sp   if (!dfn[v])         {            DFS (v);      &NBS P     Low[u]=min (Low[u],low[v]);       }        ELSE if (!belong[v]) {&nbs P           low[u]=min (Low[u],dfn[v]);       }     }  &nbs P  if (Low[u]==dfn[u])      {         scc_cnt++;        &NB Sp;while (1)       &NBsp  {             int x=s.top ();             s.pop ();             belong[x]=scc_cnt;            &NBSP;IF (x ==u) break;         }     }}void FIND_SCC (int n) {    dfs_clock=scc_cnt= 0;    memset (belong,0,sizeof (belong));    memset (dfn,0,sizeof (DFN));    for (int i=0;i <n;i++)     if (!dfn[i]) DFS (i);} int main () {    int n,i,j;    scanf ("%d", &n);    for (int i=0;i<n;i++)     {& nbsp       int x;        while (scanf ("%d", &x)!=eof&&x)       &NBS P {            x--;            G[i].push_back (x);    & nbsp  }   }    FIND_SCC (n);    if (scc_cnt==1)   &NBSp {      printf ("1\n0\n");        return 0; }  int in[n], out[n];  memset (in, 0, sizeof in);  memset (out, 0, sizeof off);  for (i=0; i<n; ++i)   for (j=0; J<g[i].size () ; ++J)   {    int v = g[i][j];    if (belong[i]! = Belong[v])     {      out [Belong[i]]++;      in  [belong[v]]++;   } }  int in_tot = 0, Out_tot = 0;&N Bsp for (I=1; i<=scc_cnt; ++i)   {    if (!in[i]) in_tot++;    if (!out[i]) out_tot++; }  printf ("%d\n%d\n", In_tot,max (In_tot,out_tot));  return 0;}

Templates for SCC

POJ 1236 Network of schools