sameTree.java

/**
 * 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) {
 return false;
 }
 if(p.val==q.val) {
 return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
 } else {
 return false;
 }
 
 }
}