100. Same Tree

判断树是否相同：若树相同，那么任意节点的左右子树均相同。

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if(p==NULL&&q==NULL)
            return 1;
         if(p==NULL||q==NULL)
            return 0;
        if(p->val!=q->val)
            return 0;
        
        return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);
        
        
    }
};