POJ 2513 Colored Sticks <trie+并查集+欧拉路径>

来源：互联网发布：网络拓扑生成器编辑：程序博客网时间：2024/06/06 03:14

题目：传送门。

分析：我好懒，直接分享一篇题解吧，传送门。

代码：

#include <iostream>#include <cstdio>#include <cstring>#include <string>#include <algorithm>#include <cmath>using namespace std;const int MAXN=25e4+5;class trieTree{public:int id;trieTree *next[27];trieTree(){id=-1;memset(next,0,sizeof next);}};trieTree root;int degree[MAXN*2];int ancestor[MAXN*2];int color;int getID(char *str){trieTree *t=&root;for(int i=0;str[i]!='\0';++i){int index=str[i]-'a';if(!t->next[index]){trieTree *tt=new trieTree;t->next[index]=tt;}t=t->next[index];}return t->id>=0 ? t->id:t->id=color++; }int find(int x){if(ancestor[x]!=x){ancestor[x]=find(ancestor[x]);}return ancestor[x];}void unionSet(int x,int y){int px=find(x),py=find(y);ancestor[py]=px;}int main(){color=0;memset(degree,0,sizeof degree);for(int i=0;i<MAXN*2;++i) ancestor[i]=i;char c1[12],c2[12];while(cin>>c1>>c2){int x=getID(c1),y=getID(c2);unionSet(x,y);degree[x]++; degree[y]++;}int r=find(1),sum=0;for(int i=0;i<color;++i){if(degree[i]&1) sum++;if(find(i)!=r){cout<<"Impossible\n";return 0;}if(sum>2){cout<<"Impossible\n";return 0;}}if(sum==1) cout<<"Impossible\n";else cout<<"Possible\n";return 0;}

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