100.相同的树Leetcode

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



//递归实现
class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        
        if(p == null && q == null){//递归的出口,也可以看做是规模最小的那种情况
            return true;
        }else{
            if(p == null || q == null){
                return false;
            }
            return ((p.val == q.val) && isSameTree(p.left, q.left) && isSameTree(p.right, q.right));//同时都不为空，如果左子树和右子树相同，则相同
        } 
    }
}