【leetcode】Same Tree（easy）

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.

思路：太简单！

bool 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);
        }
    }