rt（DEV-C++运行无误）

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N=1000005;
int next[N];
int n; 
signed main(){

	cin>>n;
	for(int i=1;i<=n;i++){
		int j,x,y;
		cin>>j;
		if(j==1){
			cin>>x>>y;
			int cmp=next[x];
			next[x]=y;
			next[y]=cmp;
		}
		else if(j==2){
			cin>>x;
			cout<<next[x]<<endl; 
		}
		else if(j==3){
      cin>>x;
			next[x]=next[next[x]];
			next[next[x]]=0;
		}
	}
	return 0;
}