题解 | #合并二叉树#

public class Solution {

    public TreeNode mergeTrees (TreeNode t1, TreeNode t2) {
        // write code here
        if(t1==null || t2==null){
            return t1==null?t2:t1;
        }
        t1.val = t1.val + t2.val;
        t1.left = mergeTrees(t1.left, t2.left);
        t1.right = mergeTrees(t1.right, t2.right);
        return t1;
    }
}