tree example

Author: mnfmnfm

Diff for: class-38/Tree.java

@@ -0,0 +1,41 @@
+import java.util.*;
+
+public class Tree {
+  int value;
+  Tree left;
+  Tree right;
+
+  public Tree() {}
+  public Tree(int value) {
+    this.value = value;
+  }
+
+  public Tree(int value, Tree left, Tree right) {
+    this.value = value;
+    this.left = left;
+    this.right = right;
+  }
+
+  public static void main(String[] args) {
+    Tree t = new Tree(1, new Tree(2, new Tree(1), new Tree(1)), new Tree(3, new Tree(1), new Tree(1)));
+    System.out.println(isBalanced(t));
+    Tree unbalanced = new Tree(1, new Tree(1, new Tree(1), null), null);
+    System.out.println(isBalanced(unbalanced));
+  }
+
+  public static boolean isBalanced(Tree input) {
+    if (input == null) {
+      return true;
+    }
+    else {
+      return isBalanced(input.left) &&
+        isBalanced(input.right) &&
+        Math.abs(height(input.left) - height(input.right)) < 2;
+    }
+  }
+
+  public static int height(Tree input) {
+    if (input == null) return 0;
+    return 1 + Math.max(height(input.left), height(input.right));
+  }
+}