p110.java

/*Given the roots of two binary trees p and q, write a function to check if they are the same or not.

Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.


Example 1:


Input: p = [1,2,3], q = [1,2,3]
Output: true
Example 2:


Input: p = [1,2], q = [1,null,2]
Output: false
Example 3:


Input: p = [1,2,1], q = [1,1,2]
Output: false
 

Constraints:

The number of nodes in both trees is in the range [0, 100].
-104 <= Node.val <= 104*/

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */

class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p==null && q==null){
            return true;
        }else if(p==null && q!=null || p!=null && q==null){
            return false;
        }else if(p.val!=q.val){
            return false;
        }else{
            return (isSameTree(p.left,q.left) && isSameTree(p.right,q.right));
        }
    }
}