Same Tree

Change-Id: I2ab046652c7fcf933ba91566d40ba686a5deab05

Author: applewjg

SameTree.java

@@ -0,0 +1,29 @@
+/*
+ Author:     King, [email protected]
+ Date:       Dec 25, 2014
+ Problem:    Same Tree
+ Difficulty: easy
+ Source:     http://leetcode.com/onlinejudge#question_100
+ Notes:
+ Given two binary trees, write a function to check if they are equal or not.
+ Two binary trees are considered equal if they are structurally identical and the nodes have the same value.
+
+ Solution: recursion.
+ */
+/**
+ * Definition for binary tree
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+public class Solution {
+    public boolean isSameTree(TreeNode p, TreeNode q) {
+        if (p == null && q == null) return true;
+        if ((p != null && q == null) || (p == null && q != null)) return false;
+        if (p.val != q.val) return false;
+        return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
+    }
+}