Tugas BST With Java

TugasBST.java

/**
 *
 * @author bagusrianto
 */
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class NodeTree{

    int item;
    NodeTree kiri;
    NodeTree kanan;

    NodeTree(int x) {
        item = x;
    }
}

/**
 *
 * @author Bagusrianto
 */
public class TugasBST {
    
    private static int hitung;
    private static NodeTree root;
    private static String alamat;
    
    private static void main(String[] args) throws IOException {
        
        int n;
        String[] ans_string;
        String s1;
        alamat = "";
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        
        n = Integer.parseInt(in.readLine());
        s1 = in.readLine();
        ans_string = s1.split(" ");
        for (int i = 0; i < n; ++i) {
            sisipPohon(Integer.parseInt(ans_string[i]));
        }
        
        n = Integer.parseInt(in.readLine());
        s1 = in.readLine();
        ans_string = s1.split(" ");
        for (int i = 0; i < n; ++i) {
            pohonBerisi(root, Integer.parseInt(ans_string[i]));
        }
    }
    
    private static boolean pohonBerisi(NodeTree simpul, int item) {
        if (simpul == null) {
            alamat = "";
            return false;
        } else if (item == simpul.item) {
            if (alamat.isEmpty()) {
                System.out.println("O");
            } else {
                System.out.println(alamat + "O");
            }
            
            alamat = "kiri " + alamat;
            return pohonBerisi(simpul.kiri, item);
        } else if (item < simpul.item) {
            alamat = "kiri " + alamat;
            return pohonBerisi(simpul.kiri, item);
        } else {
            alamat = "kanan " + alamat;
            return pohonBerisi(simpul.kanan, item);
        }
    }
    
    private static void sisipPohon(int v) {
        if (root == null) {
            root = new NodeTree(v);
            return;
        }
        NodeTree pointer;
        pointer = root;
        while (true) {
            if (v <= pointer.item) {
                if (pointer.kiri == null) {
                    pointer.kiri = new NodeTree(v);
                    return;
                } else {
                    pointer = pointer.kiri;
                }
            } else {
                if (pointer.kanan == null) {
                    pointer.kanan = new NodeTree(v);
                    return;
                } else {
                    pointer = pointer.kanan;
                }
            }
        }
    }
}