并查集的无序map形式C++

#include<iostream>
#include <unordered_map>
#include<algorithm>
using namespace std;
unordered_map<string, string> father;
string find(string x)
{
    if (father[x] == x)return x;
    else
    {
        father[x] = find(father[x]);
        return father[x];
    }
}
void merge(string x,string y)
{
    x = find(x); y = find(y);
    father[y] = x;
}
bool lian(string x,string y)
{
    x = find(x); y = find(y);
    return x == y;
}
int main() 
{
    string s, h; int n; char c; char b[100];
    cin >> n;
    while(n--)
    {
        cin >> s >> h; 
        if (father.find(s) == father.end())father[s]=s;
        if (father.find(h) == father.end())father[h]=h;
        merge(s, h);
    }
    return 0;
}