Main.java

/*
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package fr;
 
 
 
import java.util.ArrayList;
import java.util.Scanner;
 
/**
 *
 * @author kuric10
 */
@SuppressWarnings({"unchecked"})
public class Main {
 
    private static int hlavna, poc;
    private static ArrayList<int[]>[] pole;
    private static boolean[] pouzite;
 
    public static void main(String[] args) {
 
        String pom[];
        String s;
        int a, b;
        Scanner input = new Scanner(System.in);
        int[] pomPole;
        int kde;
        int pomi;
        while (input.hasNextLine()) {
            s = input.nextLine();
            pom = s.split(" ");
            hlavna = Integer.parseInt(pom[1]) - 1;
            poc = Integer.parseInt(pom[0]);
            pole = new ArrayList[poc];
            pouzite = new boolean[poc];
            for (int i = 0; i < poc; i++) {
                pole[i] = new ArrayList<>();
            }
            for (int i = 0; i < poc - 1; i++) {
                pomPole = new int[2];
                s = input.nextLine();
                pom = s.split(" ");
                a = Integer.parseInt(pom[1]) - 1;
                b = Integer.parseInt(pom[2]);
                pomPole[0] = a;
                pomPole[1] = b;
                kde = Integer.parseInt(pom[0]) - 1;
 
                pole[kde].add(pomPole);
                pomPole = new int[2];
                pomPole[0] = kde;
                pomPole[1] = b;
                pole[a].add(pomPole);
            }
 
            System.out.println(rek(hlavna, 9999999));
        }
 
    }
 
    private static int rek(int ja, int i) {
 
        pouzite[ja] = true;
 
        int sucet = 0;
        for (int[] is : pole[ja]) {
 
            if (pouzite[is[0]]) {
 
                continue;
            }
            sucet += rek(is[0], is[1]);
        }
        if (sucet == 0) {
            return i;
        }
 
        return Math.min(i, sucet);
    }
}
 

Main.java