Same Tree

给两棵树，判断是否相同，很简单

难度评价：2

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