import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;

public class Main {

	public static void getFather(ArrayList Father, ArrayList Child, int child, ArrayList FATHERS) {
 		int index = Child.indexOf(child + "");
		FATHERS.add(child + "");
		while(index >= 0) {
			FATHERS.add(Father.get(index));
			index = Child.indexOf(Father.get(index));
		}
	}
	
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		int firstline = Integer.parseInt(s);
		for(int i=0; i<firstline; i++) {
			ArrayList al1 = new ArrayList();
			ArrayList al2 = new ArrayList();
			ArrayList al3 = new ArrayList();
			ArrayList al4 = new ArrayList();
			String S = sc.nextLine();
			int secondline = Integer.parseInt(S);
			for(int k=0; k<secondline-1; k++) {
				String lines = sc.nextLine();
				al1.add(lines.split(" ")[0]);
				al2.add(lines.split(" ")[1]);
			}
			String string = sc.nextLine();
			getFather(al1, al2, Integer.parseInt((string.split(" ")[0])), al3);
			getFather(al1, al2, Integer.parseInt((string.split(" ")[1])), al4);
			outer:
			for(int I=0; I<al3.size(); I++) {
				for(int K=0; K<al4.size(); K++) {
					int numal3 =  Integer.parseInt((String)al3.get(I));
					int numal4 =   Integer.parseInt(((String)al4.get(K)));
					if(numal3 == numal4) {
						System.out.println(al3.get(I));
						break outer;
					}
				}
			}
		}
	}
}

• Re:奇妙的runtime error了，求达人指点 (1617) 737363395 2014-09-18 00:34:01