leetcode 面试题 04.10. 检查子树

leetcode

C++：

/**
 * 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 checkSubTree(TreeNode* t1, TreeNode* t2) {

        if ( !t1 || !t2 ) {

            return false;
        }

        if ( t1 -> val == t2 -> val ) {

            return checkEqual( t1, t2 );

        } else {

            if ( t1 -> left && checkSubTree( t1 -> left, t2 ) ) {

                return true;
            }

            if ( t1 -> right && checkSubTree( t1 -> right, t2 ) ) {

                return true;
            }

            return false;
        }
    }

    bool checkEqual(TreeNode* t1, TreeNode* t2) {

        if ( !t1 && !t2 ) {

            return true;
        }

        if ( !t1 || !t2 ) {

            return false;
        }

        return t1 -> val == t2 -> val && checkEqual( t1 -> left, t2 -> left ) && checkEqual( t1 -> right, t2 -> right );
    }
};