最近状态不佳，总是爱犯低级错误，比较水的题，没什么需要讲得，要说的可能是floyd判断包闭吧

void Floyd()  
{  
    for(int k=1; k<=n; k++)  
        for(int i=1; i<=n; i++)  
            if(map[i][k])  
                for(int j=1; j<=n; j++)  
                    if(map[k][j])  
                        map[i][j] = 1;  
}  

之前做了不少图论，图论周感觉能应付的过去。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<list>
#include<cmath>
#include<string>
#include<sstream>
#include<ctime>
using namespace std;
#define _PI acos(-1.0)
#define esp 1e-9
#define INF 1 << 30
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int,int> pill;
/*===========================================
===============KinderRiven===================
===========================================*/
#define MAXD 25 + 1
int n,m;
map<string,int>name;
vector<string>Name;
int G[MAXD][MAXD],id;
int vis[MAXD];
void init(){
    name.clear();
    Name.clear();
    id = 0;
    memset(G,0,sizeof(G));
    memset(vis,0,sizeof(vis));
}
void dfs(int u){
    vis[u] = 1;
    for(int i = 0 ; i < n ; i++)
        if(G[u][i] == 1 && G[u][i] == G[i][u]){
         if(!vis[i]){
            cout << ", " << Name[i];
            dfs(i);
         }
    }
}
int main(){
    int Case = 1;
    while(cin >> n >> m){
        init();
        if(!n && !m) break;
        for(int i = 0 ; i < m ; i++){
            string s1,s2;
            cin >> s1 >> s2;
            if(!name.count(s1)){
                name[s1] = id++;
                Name.push_back(s1);
            }
            if(!name.count(s2)){
                name[s2] = id++;
                Name.push_back(s2);
            }
            int x = name[s1] , y = name[s2];  /*找出2个字符串对应的ID*/
            G[x][y] = 1;                      /*连接*/
        }
        for(int k = 0 ; k < n ; k++)
            for(int i = 0 ; i < n ; i++)
                if(G[i][k])
                for(int j = 0; j < n ; j++)
                    if(G[k][j]){
                       G[i][j] = 1;
                }
        if(Case > 1)
        cout << endl;
        cout << "Calling circles for data set " << Case++ <<":" << endl;
        for(int i = 0; i < n ; i++){
            if(!vis[i]){
                cout << Name[i];
                dfs(i);
                cout << endl;
            }
        }
    }
    return 0;
}
/*
5 5
A B
A B
A B
C D
E C
*/