[LeetCode]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.

思考：DFS.

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    bool DFS(TreeNode *p,TreeNode *q)
    {
        if((p&&!q)||(!p&&q)) return false;
        if(p&&q)
        {
            if(p->val!=q->val)
            {
                return false;
            }
            return DFS(p->left,q->left)&&DFS(p->right,q->right);
        }
    }
    bool isSameTree(TreeNode *p, TreeNode *q) {
        return DFS(p,q);
    }
};