binaryTreePreorderTraversalTest.java

package binaryTreePreorderTraversal;

import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

import static org.junit.Assert.*;

/**
 * Created by leicao on 6/10/15.
 */
public class binaryTreePreorderTraversalTest {

    /**
     *          0
     *        /   \
     *      1      2
     *     / \      \
     *   3    4      6
     *      /
     *      5
     */
    @Test
    public void testPreorderTraversal() throws Exception {
        TreeNode t0 = new TreeNode(0);

        TreeNode n0 = new TreeNode(0);
        TreeNode n1 = new TreeNode(1);
        TreeNode n2 = new TreeNode(2);
        TreeNode n3 = new TreeNode(3);
        TreeNode n4 = new TreeNode(4);
        TreeNode n5 = new TreeNode(5);
        TreeNode n6 = new TreeNode(6);

        n0.left = n1;
        n0.right = n2;
        n1.left = n3;
        n1.right = n4;
        n4.left = n5;
        n2.right = n6;


        ArrayList<TreeNode> inputes = new ArrayList<TreeNode>();
        inputes.add(t0);
        inputes.add(n0);

        List<List<Integer>> results = new ArrayList<List<Integer>>(){{
            add(new ArrayList<Integer>(){{
                   add(0);
            }});
            add(new ArrayList<Integer>(){{
                add(0);
                add(1);
                add(3);
                add(4);
                add(5);
                add(2);
                add(6);
            }});
        }};

        binaryTreePreorderTraversal b = new binaryTreePreorderTraversal();
        for (int i = 0; i < results.size(); i++) {
            List<Integer> r = b.preorderTraversal(inputes.get(i));
            assertEquals(results.get(i), r);
        }

    }
}