欧拉回路+并查集（判断图的联通）+Tire树（快速查找字符串，并且记录相应点的度数）

Tire树相关知识

#include 
    
     using namespace std;const int maxc = 26;const int maxn = 500001;struct TrieNode{	int key;	TrieNode * child[maxc];	TrieNode()	{		key=-1;		memset(child,0,sizeof(child));	}};int count[maxn];TrieNode * root;int tot=-1;int insert(char * s){	if(root==NULL) root=new TrieNode;	int did;	TrieNode * tem=root;	for(;*s!='\0';s++)	{		did=*s-'a';		if(tem->child[did]==NULL)			tem->child[did]=new TrieNode;		tem=tem->child[did];	}	if(tem->key==-1)		tem->key=++tot;	count[tem->key]++;	return tem->key;}struct UFSTree{	int val;	int parent;	int rank;}t[maxn];void init(){	for(int i=0;i
     
      t[p2].rank)		t[p2].parent=p1;	else	{		t[p1].parent=p2;		if(t[p1].rank==t[p2].rank)			t[p2].rank++;	}}int main(){	char f[11],s[11];	init();	while(scanf("%s %s",f,s)!=EOF)	{		int k1=insert(f);		int k2=insert(s);		int p1=find(k1);		int p2=find(k2);		if(p1!=p2)			Union(p1,p2);	}	if(root==NULL) 	{		cout<<"Possible"<