题解 | #合并二叉树#

 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param t1 TreeNode类 
     * @param t2 TreeNode类 
     * @return TreeNode类
     */
    TreeNode* mergeTrees(TreeNode* t1, TreeNode* t2) {
        if(t1==NULL){
            return t2;
        }
        if(t2==NULL){
            return t1;
        }
        t1->val=t1->val+t2->val;
        //递归t1主树的左右子节点,同时更新主树t1的左右子树
        t1->left=mergeTrees(t1->left, t2->left);
        t1->right=mergeTrees(t1->right,t2->right);
        //返回合并后的主树节点
        return t1;
        // write code here
    }
};