有关树的测试程序和算法测试类

src/main/java/com/ossez/lang/tutorial/utils/TreeUtils.java

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+package com.ossez.lang.tutorial.utils;
+
+import java.util.ArrayList;
+
+import com.ossez.lang.tutorial.models.TreeNode;
+
+/**
+ * 
+ * @author YuCheng
+ *
+ */
+public class TreeUtils {
+
+	public static TreeNode initTree(String data) {
+		// NULL CHECK
+		if (data.equals("{}")) {
+			return null;
+		}
+
+		ArrayList<TreeNode> treeList = new ArrayList<TreeNode>();
+
+		data = data.replace("{", "");
+		data = data.replace("}", "");
+		String[] vals = data.split(",");
+
+		// INSERT ROOT
+		TreeNode root = new TreeNode(Integer.parseInt(vals[0]));
+		treeList.add(root);
+
+		int index = 0;
+		boolean isLeftChild = true;
+		for (int i = 1; i < vals.length; i++) {
+			if (!vals[i].equals("#")) {
+				TreeNode node = new TreeNode(Integer.parseInt(vals[i]));
+				if (isLeftChild) {
+					treeList.get(index).left = node;
+				} else {
+					treeList.get(index).right = node;
+				}
+				treeList.add(node);
+			}
+
+			// LEVEL
+			if (!isLeftChild) {
+				index++;
+			}
+
+			// MOVE TO RIGHT OR NEXT LEVEL
+			isLeftChild = !isLeftChild;
+		}
+
+		return root;
+
+	}
+}

src/test/java/com/ossez/lang/tutorial/tests/TreeTest.java

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+package com.ossez.lang.tutorial.tests;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.ossez.lang.tutorial.models.TreeNode;
+import com.ossez.lang.tutorial.utils.TreeUtils;
+
+/**
+ * 
+ * @author YuCheng
+ *
+ */
+public class TreeTest {
+	private final static Logger logger = LoggerFactory.getLogger(TreeTest.class);
+	private static List<Integer> loopList = new ArrayList<Integer>();
+
+	@Test
+	public void testMain() {
+		logger.debug("TREE TEST");
+		String data = "{1,2,3,4,5,#,6,#,#,7,8,#,#}";
+		TreeNode treeNode = TreeUtils.initTree(data);
+
+		// PRE
+		loopList = new ArrayList<Integer>();
+		preOrderTraverselRecursion(treeNode);
+		System.out.println(loopList);
+
+		// IN
+		loopList = new ArrayList<Integer>();
+		inOrderTraverselRecursion(treeNode);
+		System.out.println(loopList);
+
+		// POST
+		loopList = new ArrayList<Integer>();
+		postOrderTraversalRecursion(treeNode);
+		System.out.println(loopList);
+	}
+	
+	
+	
+
+	/**
+	 * 
+	 * @param root
+	 */
+	public void preOrderTraverselRecursion(TreeNode root) {
+		if (root != null) {
+			loopList.add(root.val);
+			preOrderTraverselRecursion(root.left);
+			preOrderTraverselRecursion(root.right);
+		}
+	}
+
+	/**
+	 * 
+	 * @param root
+	 */
+	public void inOrderTraverselRecursion(TreeNode root) {
+		if (root != null) {
+			inOrderTraverselRecursion(root.left);
+			loopList.add(root.val);
+			inOrderTraverselRecursion(root.right);
+		}
+
+	}
+
+	/**
+	 * 
+	 * @param root
+	 */
+	public void postOrderTraversalRecursion(TreeNode root) {
+		if (root != null) {
+			postOrderTraversalRecursion(root.left);
+			postOrderTraversalRecursion(root.right);
+			loopList.add(root.val);
+		}
+
+	}
+
+}