Tree Updates

Tree Updates

Author: careermonk

bin/chapter6trees/DiameterOfTree.class

@@ -15,5 +15,36 @@
 package chapter6trees;
 
 public class DiameterOfTree {
+	public static int diameter = 0;
+	
+	public int diameterOfTree(BinaryTreeNode root){
+		int left, right;
+		if(root == null) 
+			return 0;
+		left = diameterOfTree(root.getLeft());
+		right = diameterOfTree(root.getRight());
+		if(left + right > diameter)
+			diameter = left + right;
+			return Math.max(left, right)+1;
+	}
+	// Alternative Coding
+	public int diameter(BinaryTreeNode root){
+		if(root==null) return 0;
 
+		//the path goes through the root
+		int len1 = height(root.left) + height(root.right) +3;
+
+		//the path does not pass the root
+		int len2 = Math.max(diameter(root.left), diameter(root.right));
+
+		return Math.max(len1, len2);
+	}
+	public int height(BinaryTreeNode root) {
+		if(root == null) 
+			return 0;
+		/* compute the depth of each subtree */
+		int leftDepth = height(root.getLeft());
+		int rightDepth = height(root.right);
+		return (leftDepth > rightDepth) ? leftDepth + 1 : rightDepth + 1;
+	} 
 }

bin/chapter6trees/FindLevelwithMaxSum.class

@@ -14,7 +14,6 @@
 
 package chapter6trees;
 
-import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.Queue;