Main.java

/*
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import java.io.*;
import java.util.*;
 
 
/**
 *
 * @author cteam028
 */
public class Main {
 
    /**
     * @param args the command line arguments
     */
    static Node[] nodea;
 
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line;
        while((line = br.readLine()) != null) {
            int nodes, root;
            String a[] = line.split(" ");
            nodes = Integer.parseInt(a[0]);
            root = Integer.parseInt(a[a.length-1]);
 
            nodea = new Node[nodes+1];
 
            for(int i = 0 ; i <= nodes; i++) {
                nodea[i] = new Node();
            }
            for(int i = 0; i < nodes-1;i++) {
                int b[] = new int[3];
                parseIntArr(br.readLine().toCharArray(), b);
 
                nodea[b[0]].childs.add(new Edge(b[1], b[2]));
                nodea[b[1]].childs.add(new Edge(b[0], b[2]));
            }
 
            System.out.println(compute(root));
        }
    }
 
    static int compute(int node) {
        nodea[node].used = true;
        int sum = 0;
        boolean found = false;
        for(Edge e : nodea[node].childs) {
            if(nodea[e.endNode].used) continue;
            else {
                sum += Math.min(compute(e.endNode), e.weight);
                found = true;
            }
        }
 
        if(found) return sum;
        else return Integer.MAX_VALUE;
    }
 
    public static void parseIntArr(char[] arr, int[] target)
    {
        int i = 0;
        int acc = -1;
 
        for(char ch :arr)
        {
            if(ch == ' ')
            {
                if(acc!= -1)
                {
                    target[i++] = acc;
                    acc = -1;
                }
            }
            else if(acc == -1)
                acc = ch - '0';
            else
                acc = acc * 10 + (ch - '0');
        }
        if(acc != -1)
            target[i] = acc;
    }
 
}
 
class Node {
    LinkedList<Edge> childs = new LinkedList<Edge>();
    boolean used = false;
}
class Edge {
    int endNode, weight;
    public Edge(int a, int b) {
        endNode = a;
        weight = b;
    }
}