LeetCode刷题笔录 Same Tree

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.

基本的递归。先比较当前node，再比较左子树和右子树

public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p == null && q == null)
            return true;
        else if(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);
    }
}