割点割边

#include < iostream >
using   namespace  std;
int  bridge[N][ 2 ];
int  col[N],low[N],dep[N],iscut[N],nb;
int  dfs( int  u, int  fa, int  depth)
{
    col[u] = 1 ;
    dep[u] = low[u] = depth;
     int  tol = 0 ;
     int  tofa = 0 ; // 判断u,v之间是否有两条以上边
     int  i,v;
     for (i = 0 ;i < list[u].size();i ++ )
    {
        v = list[u][i];
         if (col[v] == 0 )
        {
            tol ++ ;
            dfs(v,u,depth + 1 );
            low[u] = min(low[u],low[v]);
             /* 求割点
            if(u==root&&col>1||x!=root&&low[v]>=dep[u])
                  iscut[u]=1;
             */
             /* 求桥
            if(low[v]>dep[u])
            {
                bridge[++nb][0]=u;
                bridge[nb][1]=v;
            }
             */
        }
         else
        {
             if (v != fa || tofa)
                low[u] = min(low[u],dep[v]);
             else
                tofa = 1 ;
        }
    }
     return   0 ;
}
int  main()
{
    
    root = 1 ;
    dfs(root, - 1 , 1 );
    
}