LeetCode 100. Same Tree (C++)

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：前序遍历，判断两树对应node要么都为空，要么都不为空。并且对应node的值必须相等。

class Solution {
public:
bool isSameTree(TreeNode* p, TreeNode* q) {
if (!p && !q) return true;
if ((!p && q)||(p && !q)) return false;

return ((p->val == q->val) && isSameTree(p->left, q->left) && isSameTree(p->right, q->right));
}
};