Codeforces Round #541--1131F. Asya And Kittens(基础并查集)

https://codeforces.com/contest/1131/problem/F

#include<bits/stdc++.h>

using namespace std;

int n;

vector<vector<int> > v;

vector<int> par;

int find(int d){

    if(d==par[d])

        return d;

    else

        return par[d]=find(par[d]);

}

void unite(int x,int y){

    x=find(x);

    y=find(y);

    if(v[x].size()<v[y].size())

        swap(x,y);

    for(int i=;i<v[y].size();i++)

        v[x].push_back(v[y][i]);

    par[y]=x;

}

int main(){

    int n;

    cin>>n;

    v.resize(n+);

    par.resize(n+);

    for(int i=;i<=n;i++){

        par[i]=i;

        v[i].push_back(i);

    }

    for(int i=;i<n-;i++){

        int a,b;

        cin>>a>>b;

        unite(a,b);

    }

    for(int x:v[find()])cout<<x<<' ';

    cout<<endl;

    return ;

}