LeetCode 951 翻转等价二叉树

/**
 * 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 flipEquiv(TreeNode* root1, TreeNode* root2) {
        if(root1==NULL&&root2==NULL){
            return true;
        }
        if(root1==NULL||root2==NULL||root1->val!=root2->val){
            return false;
        }
        return (flipEquiv(root1->left,root2->left)&&flipEquiv(root1->right,root2->right))||
                (flipEquiv(root1->left,root2->right)&&flipEquiv(root1->right,root2->left));
    }
};