Language: C++

#include <bits/stdc++.h>
using namespace std;

	int main() {
	
      int N;
      cin >> N >> endl;
      Node v[] = new Node[N];
		int c[] = new int[N-1];
		for(int i=0;i<N;i++){
			v[i] = new Node(i);
		}
		Edge e[] = new Edge[N-1];
		for(int i=0;i<N-1;i++) {
          cin >> a >> b >> c >> endl;
			e[i] = new Edge[a-1],v[b-1],c);
		}
		int Q;
      cin >> Q >> endl;
		int K;
      cin >> K >> endl;
		int x[] = new int[Q];
		int y[] = new int[Q];
		for(int i=0;i<Q;i++) {
			cin >> x[i] >> endl;
			cin >> y[i] >> endl;
		}
		PriorityQueue<Node> searching = new PriorityQueue<>((u,w)->u.d>w.d?1:u.d<w.d?-1:0);
		PriorityQueue<Node> searched = new PriorityQueue<>((u,w)->u.d>w.d?1:u.d<w.d?-1:0);
		boolean used[] = new boolean[N];
		Arrays.fill(used, false);
		v[K-1].Reload_dist(0);
		used[K-1] = true;
		for(Edge connect:v[K-1].edges) {
			Node another = connect.Other_one(v[K-1]);
			another.Reload_dist(connect.cost);
			searching.add(another);
			used[another.id] = true;
		}
		searched.add(v[K-1]);

		Node vertex=null;
		while(searching.size()>0) {
			vertex = searching.poll();
			for(Edge connect:vertex.edges) {
				Node another = connect.Other_one(vertex);
				if(!used[another.id]) {
					another.Reload_dist(vertex.d + connect.cost);
					if(!searched.contains(another)){
						searching.add(another);
					}
					searched.add(vertex);
					used[another.id] = true;
				}
			}
		}
		long result = 0;
		for(int i=0;i<Q;i++) {
			result = v[x[i]-1].d + v[y[i]-1].d;
			cout << result << endl;
		}




		return 0;
	}

void Node{
	int id;
	long d;
	Node prev = null;
	ArrayList<Edge> edges = new ArrayList<>();

	public Node(int id) {
		this.id = id;
		this.d = Integer.MAX_VALUE;
	}

	public void Reset() {
		this.d = Integer.MAX_VALUE;
		this.prev = null;
	}

	public void Reload_dist(long dist) {
		this.d = dist;
	}

	public void Reload_prev(Node v) {
		this.prev = v;
	}

	@Override public Node clone() {
		return new Node(this.id);
	}

	public void Connect(Edge e) {
		edges.add(e);
	}
}

void Edge{
	Node v1, v2;
	int cost;
	public Edge(Node id1,Node id2, int c) {
		this.v1 = id1;
		this.v2 = id2;
		this.cost = c;
		v1.Connect(this);
		v2.Connect(this);
	}

	public Node First_one() {
		return this.v1;
	}

	public Node Second_one() {
		return this.v2;
	}

	public Node Other_one(Node v) {
		if(v.equals(this.v1)) {
			return this.v2;
		}
		else {
			return this.v1;
		}
	}
}

void Graph{
	static Node[] nodes;
	static Edge[] edges;

	public Graph(Node[] v,Edge[] e) {
		Graph.nodes = v;
		Graph.edges = e;
	}

	public static int size() {
		return nodes.length;
	}

	public boolean Bellman_Ford(Node s) {
		boolean negative_loop[] = new boolean[size()];
		Arrays.fill(negative_loop, false);
		s.Reload_dist(0);
		for(int i=0;i<size();i++) {
			for(Node v : nodes) {
				for(Edge e : v.edges) {
					if((v.d != Long.MAX_VALUE && e.Other_one(v).d > v.d + e.cost)) {
						e.Other_one(v).Reload_dist(v.d + e.cost);
						negative_loop[e.Other_one(v).id] = true;
					}
					if(i==size()-1) {
						return true;
					}
				}
			}
		}
		return false;
	}

}



Compiler output:
a.cc:93:9: error: stray '@' in program
   93 |         @Override public Node clone() {
      |         ^
a.cc: In function 'int main()':
a.cc:7:16: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and '<unresolved overloaded function type>')
    7 |       cin >> N >> endl;
      |       ~~~~~~~~~^~~~~~~
In file included from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:24: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'bool&'
  170 |       operator>>(bool& __n)
      |                  ~~~~~~^~~
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]'
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:25: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'short int&'
  174 |       operator>>(short& __n);
      |                  ~~~~~~~^~~
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:34: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'short unsigned int&'
  177 |       operator>>(unsigned short& __n)
      |                  ~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]'
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:23: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'int&'
  181 |       operator>>(int& __n);
      |                  ~~~~~^~~
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:32: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'unsigned int&'
  184 |       operator>>(unsigned int& __n)
      |                  ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:24: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long int&'
  188 |       operator>>(long& __n)
      |                  ~~~~~~^~~
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:33: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long unsigned int&'
  192 |       operator>>(unsigned long& __n)
      |                  ~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:29: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long long int&'
  199 |       operator>>(long long& __n)
      |                  ~~~~~~~~~~~^~~
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:38: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long long unsigned int&'
  203 |       operator>>(unsigned long long& __n)
      |                  ~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:25: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'float&'
  219 |       operator>>(float& __f)
      |                  ~~~~~~~^~~
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:26: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'double&'
  223 |       operator>>(double& __f)
      |                  ~~~~~~~~^~~
/usr/include/c++/14/istream:227:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:31: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long double&'
  227 |       operator>>(long double& __f)
      |                  ~~~~~~~~~~~~~^~~
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:25: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'void*&'
  328 |       operator>>(void*& __p)
      |                  ~~~~~~~^~~
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:36: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'}
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |                  ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/istream:126:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>; __ios_type = std::basic_ios<char>]'
  126 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:126:32: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'}
  126 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |                  ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/usr/include/c++/14/istream:133:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  133 |       operator>>(ios_base& (*__pf)(ios_base&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:133:30: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::ios_base& (*)(std::ios_base&)'
  133 |       operator>>(ios_base& (*__pf)(ios_base&))
      |                  ~~~~~~~~~~~~^~~~~~~~~~~~~~~~
/usr/include/c++/14/istream:352:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; __streambuf_type = std::basic_streambuf<char>]'
  352 |       operator>>(__streambuf_type* __sb);
      |