100.Same Tree

description:
Given two binary trees, 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.

Example 1:

Input: 1 1
/ \ /
2 3 2 3

    [1,2,3],   [1,2,3]

Output: true

Example 2:

Input: 1 1
/
2 2

    [1,2],     [1,null,2]

Output: false

Example 3:

Input: 1 1
/ \ /
2 1 1 2

    [1,2,1],   [1,1,2]

Output: false

**tips:**判断树是否相同，通过深度遍历的方式实现。
solution:

class Solution {
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if(!p && !q) return true;
        if((!p && q)||(p && !q)||(p->val != q->val)) return false;
        return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right); 
    }
};