奇怪的是，我的判定是不是联通的部分出问题了

先贴个对的：

#include <cstdio>
#include <map>
#include <cstring>
#include <string>
#include <iostream>
using namespace std;

const int SIZE = 100000+10;
const int SSIZE = 1000 +10;
const int tb = 26;

int idx(char x)
{
    return x-'a';
}

int n,parent[tb],ideg[tb],odeg[tb],e[tb];

void init()
{
    for(int i=0;i<tb;i++)
    {
        parent[i]=i;
        e[i]=ideg[i]=odeg[i]=0;
    }
}

int Find(int x)
{
    if(x!=parent[x])parent[x]=Find(parent[x]);
    return parent[x];
}

void Union(int x, int y)
{
    x=Find(x);
    y=Find(y);
    if(x!=y)parent[y]=x;
}

int main()
{
    //freopen("poj1386.txt","r",stdin);
    int ncase;
    char str[SIZE];
    scanf("%d",&ncase);
    while(ncase--)
    {
        int u,v;
        scanf("%d",&n);
        init();
        for(int i=0;i<n;i++)
        {
            scanf("%s",str);
            ideg[ u=idx( str[strlen(str)-1]) ]++;
            odeg[ v=idx( str[0]) ]++;
            e[u]=e[v]=1;
            Union(u, v);
        }

        int connect=1,tmp=Find(u);

        for(int i=0;i<tb;i++)
        {
            if(e[i]&&tmp!=Find(i))
            {
                connect=0;
                break;
            }
        }

        if(!connect)
        {
            printf("The door cannot be opened.\n");
            continue;
        }
        /*int scnt=0;
        for(int i=0;i<tb;i++)
            if(e[i] && Find(i) == i)
                scnt++;
        if(scnt>1)
        {
            printf("The door cannot be opened.\n");
            continue;
        }*/

        int acnt=0,bcnt=0,cnt=0;
        for(int i=0;i<tb;i++)
            if(e[i])
            {
                if(ideg[i] == odeg[i])continue;
                if(ideg[i] == odeg[i]+1 )
                {
                    acnt++;
                    continue;
                }
                if(odeg[i] == ideg[i]+1 )
                {
                    bcnt++;
                    continue;
                }
                cnt++;
            }
        //if(cnt){printf("The door cannot be opened.\n");continue;}
        if((!acnt&&!bcnt&&!cnt) || (acnt==1&&bcnt==1&&cnt==0))printf("Ordering is possible.\n");
        //if(acnt<=1 && bcnt<=1)printf("Ordering is possible.\n");
        else printf("The door cannot be opened.\n");
    }
    return 0;
}

        int connect=1,tmp,i;
        for(i=0;i<tb;i++)
            if(e[i])
            {
                tmp=Find(i);
               // i--;
                break;
            }

        for(;i<tb;i++)
            if(e[i] && tmp!=Find(i))
        {
            connect=0;
            break;
        }

poj 1386 欧拉回路判定