LeetCode - 100. Same Tree(Tree, DFS, BFS, Rcursion)*

문제

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.

https://leetcode.com/problems/same-tree/

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

풀이

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