poj 3352 边连通分量

思路与poj3177一模一样。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define Maxn 1010
#define Maxm Maxn*Maxn
#define inf 0x7fffffff
using namespace std;
int dfn[Maxn],low[Maxn],degree[Maxn],e,n,lab,index[Maxn];
struct Edge{
    int to,from,next,v;
}edge[Maxm];
void init()
{
    memset(dfn,0,sizeof(dfn));
    memset(low,0,sizeof(low));
    memset(degree,0,sizeof(degree));
    memset(index,-1,sizeof(index));
    e=lab=0;
}
void addedge(int from, int to)
{
    edge[e].v=0;
    edge[e].from=from;
    edge[e].to=to;
    edge[e].next=index[from];
    index[from]=e++;
    edge[e].v=0;
    edge[e].from=to;
    edge[e].to=from;
    edge[e].next=index[to];
    index[to]=e++;
}
void dfs(int u)
{
    dfn[u]=low[u]=++lab;
    int i,j,temp;
    for(i=index[u];i!=-1;i=edge[i].next)
    {
        temp=edge[i].to;
        if(edge[i].v) continue;
        edge[i].v=edge[i^1].v=1;
        if(!dfn[temp])
        {
            dfs(temp);
            low[u]=min(low[u],low[temp]);
        }
        low[u]=min(low[u],dfn[temp]);
    }
}
int solve()
{
    int i,j,temp=0;
    for(i=1;i<=n;i++)
    {
        for(j=index[i];j!=-1;j=edge[j].next)
        {
            if(low[i]!=low[edge[j].to])
                degree[low[i]]++;
        }
    }
    for(i=1;i<=n;i++)
        if(degree[i]==1)
            temp++;
    return (temp+1)/2;
}
int main()
{
    int m,i,j,a,b;
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        init();
        for(i=1;i<=m;i++)
        {
            scanf("%d%d",&a,&b);
            addedge(a,b);
        }            
        dfs(1);
        printf("%d\n",solve());
        
    }
    return 0;
}