正题

题目链接：
https://www.luogu.org/problemnew/show/P2814

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大意

有n个父子关系（可能不止一个孩子），询问一些人最大的祖先

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代码

#include<cstdio>
#include<map>
#include<string>
#include<iostream>
using namespace std;
map<string,string> father;//map库
string name,fathers;
char c;
string find(string x)
{if (x!=father[x]) return father[x]=find(father[x]);return father[x];
}
void unionn(string x,string y)
{string fa=find(x),fb=find(y);father[fa]=fb;
}
int main()
{while (true){cin>>c;if (c=='$') break;cin>>name;if (father[name]=="") father[name]=name;if (c=='#'){fathers=name;//记录父亲}if (c=='+'){unionn(name,fathers);//连接}if (c=='?'){cout<<name<<' '<<find(name)<<endl;//询问}}
}